# Climate Indicators

`xclim.core.indicator.Indicator`

instances essentially perform the same computations as the functions
found in the `xclim.indices`

library, but also run a number of health checks on input data
and assign attributes to the output arrays. So for example, if there are missing values in
a time series, indices won’t notice, but indicators will return NaNs for periods with missing
values (depending on the missing values algorithm selected, see Missing values identification). Indicators also check that the input data has the expected frequency (e.g. daily) and that
it is indeed the expected variable (e.g. a precipitation flux). The output is assigned attributes
that conform as much as possible with the CF-Convention.

Indicators are split into realms (atmos, land, seaIce), according to the variables they operate on. See Defining new indicators for instruction on how to create your own indicators. This page lists all indicators with a summary description, click on the names to get to the complete docstring of each indicator.

## atmos: Atmosphere

`atmos.biologically_effective_degree_days`

:**Biologically effective degree days**-
**Description:**Considers daily minimum and maximum temperature with a given base threshold between 1 April and 31 October, with a maximum daily value for cumulative degree days (typically 9°C), and integrates modification coefficients for latitudes between 40°N and 50°N as well as for swings in daily temperature range. Metric originally published in Gladstones (1992).

**Based on**`xclim.indices.biologically_effective_degree_days`

**Produces:**`bedd: Integral of mean daily temperature above 10 degc, with maximum value of 9 degc, multiplied by day-length coefficient and temperature range modifier based on gladstones method for days between 04-01 and 11-01 [K days]`

`atmos.calm_days`

:**Calm days**-
**Description:**Number of days with surface wind speed below threshold.

**Based on**`xclim.indices.calm_days`

**Produces:**`calm_days: Number of days with surface wind speed below 2 m s-1 [days]`

`atmos.cffwis_indices`

:**Canadian Fire Weather Index System indices.**-
**Id:**cffwis

**Description:**Computes the 6 fire weather indexes as defined by the Canadian Forest Service: the Drought Code, the Duff-Moisture Code, the Fine Fuel Moisture Code, the Initial Spread Index, the Build Up Index and the Fire Weather Index.

**Based on**`xclim.indices.cffwis_indices`

**Produces:**`dc: Drought code []`

`dmc: Duff moisture code []`

`ffmc: Fine fuel moisture code []`

`isi: Initial spread index []`

`bui: Buildup index []`

`fwi: Fire weather index []`

`atmos.cold_and_dry_days`

:**Cold and dry days**-
**Description:**Number of days with temperature below a given percentile and precipitation below a given percentile.

**Based on**`xclim.indices.cold_and_dry_days`

**Produces:**`cold_and_dry_days: Number of days where temperature is below {unknown}th percentile and precipitation is below {unknown}th percentile [days]`

`atmos.cold_and_wet_days`

:**Cold and wet days**-
**Description:**Number of days with temperature below a given percentile and precipitation above a given percentile.

**Based on**`xclim.indices.cold_and_wet_days`

**Produces:**`cold_and_wet_days: Number of days where temperature is below {unknown}th percentile and precipitation is above {unknown}th percentile [days]`

`atmos.cold_spell_days`

:**Cold spell days**-
**Description:**The number of days that are part of a cold spell. A cold spell is defined as a minimum number of consecutive days with mean daily temperature below a given threshold.

**Based on**`xclim.indices.cold_spell_days`

**Produces:**`cold_spell_days: Total number of days constituting events of at least 5 consecutive days where the mean daily temperature is below -10 degc [days]`

`atmos.cold_spell_duration_index`

:**Cold Spell Duration Index (CSDI)**-
**Description:**Number of days part of a percentile-defined cold spell. A cold spell occurs when the daily minimum temperature is below a given percentile for a given number of consecutive days.

**Based on**`xclim.indices.cold_spell_duration_index`

**Produces:**`csdi_6: Total number of days constituting events of at least 6 consecutive days where the daily minimum temperature is below the {unknown}th percentile [days]`

`atmos.cold_spell_frequency`

:**Cold spell frequency**-
**Description:**The number of cold spell events. A cold spell is defined as a minimum number of consecutive days with mean daily temperature below a given threshold.

**Based on**`xclim.indices.cold_spell_frequency`

**Produces:**`cold_spell_frequency: Total number of series of at least 5 consecutive days where the mean daily temperature is below -10 degc []`

`atmos.consecutive_frost_days`

:**Consecutive frost days**-
**Description:**Maximum number of consecutive days where the daily minimum temperature is below 0°C

**Based on**`xclim.indices.maximum_consecutive_frost_days`

**Produces:**`consecutive_frost_days: Maximum number of consecutive days where minimum daily temperature is below 0 degc [days]`

`atmos.cool_night_index`

:**Cool night index**-
**Description:**A night coolness variable which takes into account the mean minimum night temperatures during the month when ripening usually occurs beyond the ripening period.

**Based on**`xclim.indices.cool_night_index`

**Produces:**`cool_night_index: Cool night index [degC]`

`atmos.cooling_degree_days`

:**Cooling degree days**-
**Description:**The cumulative degree days for days when the mean daily temperature is above a given threshold and buildings must be air conditioned.

**Based on**`xclim.indices.cooling_degree_days`

**Produces:**`cooling_degree_days: Cumulative sum of temperature degrees for mean daily temperature above 18.0 degc [K days]`

`atmos.corn_heat_units`

:**Corn heat units**-
**Description:**A temperature-based index used to estimate the development of corn crops. Corn growth occurs when the daily minimum and maximum temperatures exceed given thresholds.

**Based on**`xclim.indices.corn_heat_units`

**Produces:**`chu: Corn heat units (tmin > 4.44 degc and tmax > 10 degc) []`

`atmos.daily_freezethaw_cycles`

:**Daily freeze-thaw cycles**-
**Id:**dlyfrzthw

**Description:**The number of days with a freeze-thaw cycle. A freeze-thaw cycle is defined as a day where maximum daily temperature is above a given threshold and minimum daily temperature is at or below a given threshold, usually 0°C for both.

**Based on**`xclim.indices.multiday_temperature_swing`

**Produces:**`dlyfrzthw: Number of days where maximum daily temperatures are above 0 degc and minimum daily temperatures are at or below 0 degc [days]`

`atmos.daily_pr_intensity`

:**Simple Daily Intensity Index**-
**Id:**sdii

**Description:**Average precipitation for days with daily precipitation above a given threshold.

**Based on**`xclim.indices.daily_pr_intensity`

**Produces:**`sdii: Average precipitation during days with daily precipitation over 1 mm/day (simple daily intensity index: sdii) [mm d-1]`

`atmos.daily_temperature_range`

:**Mean of daily temperature range**-
**Id:**dtr

**Description:**The average difference between the daily maximum and minimum temperatures.

**Based on**`xclim.indices.daily_temperature_range`

**Produces:**`dtr: Mean diurnal temperature range [K]`

`atmos.daily_temperature_range_variability`

:**Variability of daily temperature range**-
**Id:**dtrvar

**Description:**The average day-to-day variation in daily temperature range.

**Based on**`xclim.indices.daily_temperature_range_variability`

**Produces:**`dtrvar: Mean diurnal temperature range variability [K]`

`atmos.days_over_precip_doy_thresh`

:**Number of days with precipitation above a given daily percentile**-
**Description:**Number of days in a period where precipitation is above a given daily percentile and a fixed threshold.

**Based on**`xclim.indices.days_over_precip_thresh`

**Produces:**`days_over_precip_doy_thresh: Number of days with daily precipitation flux above the {unknown}th percentile of {unknown} [days]`

`atmos.days_over_precip_thresh`

:**Number of days with precipitation above a given percentile**-
**Description:**Number of days in a period where precipitation is above a given percentile, calculated over a given period and a fixed threshold.

**Based on**`xclim.indices.days_over_precip_thresh`

**Produces:**`days_over_precip_thresh: Number of days with precipitation flux above the {unknown}th percentile of {unknown} [days]`

`atmos.days_with_snow`

:**Days with snowfall**-
**Description:**Number of days with snow between a lower and upper limit.

**Based on**`xclim.indices.days_with_snow`

**Produces:**`days_with_snow: Number of days with solid precipitation flux between 0 kg m-2 s-1 and 1e6 kg m-2 s-1 thresholds [days]`

`atmos.degree_days_exceedance_date`

:**Degree day exceedance date**-
**Description:**The day of the year when the sum of degree days exceeds a threshold, occurring after a given date. Degree days are calculated above or below a given temperature threshold.

**Based on**`xclim.indices.degree_days_exceedance_date`

**Produces:**`degree_days_exceedance_date: Day of year when the integral of mean daily temperature > 0 degc exceeds 25 k days []`

`atmos.drought_code`

:**Daily drought code**-
**Id:**dc

**Description:**The Drought Index is part of the Canadian Forest-Weather Index system. It is a numerical code that estimates the average moisture content of organic layers.

**Based on**`xclim.indices.drought_code`

**Produces:**`dc: Drought code []`

`atmos.dry_days`

:**Number of dry days**-
**Description:**The number of days with daily precipitation under a given threshold.

**Based on**`xclim.indices.dry_days`

**Produces:**`dry_days: Number of dry days [days]`

`atmos.dry_spell_frequency`

:**Dry spell frequency**-
**Description:**The frequency of dry periods of `N` days or more, during which the accumulated or maximum precipitation over a given time window of days is below a given threshold.

**Based on**`xclim.indices.dry_spell_frequency`

**Produces:**`dry_spell_frequency: Number of dry periods of 3 day(s) or more, during which the total precipitation on a window of 3 day(s) is below 1.0 mm. []`

`atmos.dry_spell_total_length`

:**Dry spell total length**-
**Description:**The total length of dry periods of `N` days or more, during which the accumulated or maximum precipitation over a given time window of days is below a given threshold.

**Based on**`xclim.indices.dry_spell_total_length`

**Produces:**`dry_spell_total_length: Number of days in dry periods of 3 day(s) or more, during which the total precipitation within windows of 3 day(s) is under 1.0 mm. [days]`

`atmos.extreme_temperature_range`

:**Extreme temperature range**-
**Id:**etr

**Description:**The maximum of the maximum temperature minus the minimum of the minimum temperature.

**Based on**`xclim.indices.extreme_temperature_range`

**Produces:**`etr: Intra-period extreme temperature range [K]`

`atmos.fire_season`

:**Fire season mask.**-
**Description:**Binary mask of the active fire season, defined by conditions on consecutive daily temperatures and, optionally, snow depths.

**Based on**`xclim.indices.fire_season`

**Produces:**`fire_season: Fire season mask []`

`atmos.first_day_above`

:**First day above**-
**Description:**Calculates the first day of a period when the temperature is higher than a certain threshold during a given number of days, after a given calendar date.

**Based on**`xclim.indices.first_day_temperature_above`

**Produces:**`first_day_above: First day of year with temperature above threshold []`

`atmos.first_day_below`

:**First day below**-
**Description:**Calculates the first day of a period when the temperature is lower than a certain threshold during a given number of days, after a given calendar date.

**Based on**`xclim.indices.first_day_temperature_below`

**Produces:**`first_day_below: First day of year with temperature below threshold []`

`atmos.first_day_tg_above`

:**First day of temperatures superior to a given temperature threshold.**-
**Description:**Returns first day of period where temperature is superior to a threshold over a given number of days (default: 1), limited to a starting calendar date (default: January 1).

**Based on**`xclim.indices.first_day_temperature_above`

**Produces:**`first_day_tg_above: First day of year with a period of at least 1 days of mean temperature above 0 degc []`

`atmos.first_day_tg_below`

:**First day of temperatures inferior to a given temperature threshold.**-
**Description:**Returns first day of period where temperature is inferior to a threshold over a given number of days (default: 1), limited to a starting calendar date (default: July 1).

**Based on**`xclim.indices.first_day_temperature_below`

**Produces:**`first_day_tg_below: First day of year with a period of at least 1 days of mean temperature below 0 degc []`

`atmos.first_day_tn_above`

:**First day of temperatures superior to a given temperature threshold.**-
**Description:**Returns first day of period where temperature is superior to a threshold over a given number of days (default: 1), limited to a starting calendar date (default: January 1).

**Based on**`xclim.indices.first_day_temperature_above`

**Produces:**`first_day_tn_above: First day of year with a period of at least 1 days of minimum temperature above 0 degc []`

`atmos.first_day_tn_below`

:**First day of temperatures inferior to a given temperature threshold.**-
**Description:**Returns first day of period where temperature is inferior to a threshold over a given number of days (default: 1), limited to a starting calendar date (default: July 1).

**Based on**`xclim.indices.first_day_temperature_below`

**Produces:**`first_day_tn_below: First day of year with a period of at least 1 days of minimum temperature below 0 degc []`

`atmos.first_day_tx_above`

:**First day of temperatures superior to a given temperature threshold.**-
**Description:**Returns first day of period where temperature is superior to a threshold over a given number of days (default: 1), limited to a starting calendar date (default: January 1).

**Based on**`xclim.indices.first_day_temperature_above`

**Produces:**`first_day_tx_above: First day of year with a period of at least 1 days of maximum temperature above 0 degc []`

`atmos.first_day_tx_below`

:**First day of temperatures inferior to a given temperature threshold.**-
**Description:**Returns first day of period where temperature is inferior to a threshold over a given number of days (default: 1), limited to a starting calendar date (default: July 1).

**Based on**`xclim.indices.first_day_temperature_below`

**Produces:**`first_day_tx_below: First day of year with a period of at least 1 days of maximum temperature below 0 degc []`

`atmos.first_snowfall`

:**First day where solid precipitation flux exceeded a given threshold**-
**Description:**The first day where the solid precipitation flux exceeded a given threshold during a time period.

**Based on**`xclim.indices.first_snowfall`

**Produces:**`first_snowfall: Date of first day where the solid precipitation flux exceeded 0.5 mm/day []`

`atmos.fraction_over_precip_doy_thresh`

:-
**Description:**Percentage of the total precipitation over period occurring in days when the precipitation is above a threshold defining wet days and above a given percentile for that day.

**Based on**`xclim.indices.fraction_over_precip_thresh`

**Produces:**`fraction_over_precip_doy_thresh: Fraction of precipitation due to days with daily precipitation above {unknown}th daily percentile []`

`atmos.fraction_over_precip_thresh`

:**Fraction of precipitation due to wet days with daily precipitation over a given percentile.**-
**Description:**Percentage of the total precipitation over period occurring in days when the precipitation is above a threshold defining wet days and above a given percentile for that day.

**Based on**`xclim.indices.fraction_over_precip_thresh`

**Produces:**`fraction_over_precip_thresh: Fraction of precipitation due to days with precipitation above {unknown}th daily percentile []`

`atmos.freezethaw_spell_frequency`

:**Freeze-thaw spell frequency**-
**Description:**Frequency of daily freeze-thaw spells. A freeze-thaw spell is defined as a number of consecutive days where maximum daily temperatures are above a given threshold and minimum daily temperatures are at or below a given threshold, usually 0°C for both.

**Based on**`xclim.indices.multiday_temperature_swing`

**Produces:**`freezethaw_spell_frequency: Frequency of events where maximum daily temperatures are above 0 degc and minimum daily temperatures are at or below 0 degc for at least 1 consecutive day(s). [days]`

`atmos.freezethaw_spell_max_length`

:**Maximal length of freeze-thaw spells**-
**Description:**Maximal length of daily freeze-thaw spells. A freeze-thaw spell is defined as a number of consecutive days where maximum daily temperatures are above a given threshold and minimum daily temperatures are at or below a threshold, usually 0°C for both.

**Based on**`xclim.indices.multiday_temperature_swing`

**Produces:**`freezethaw_spell_max_length: Maximal length of events where maximum daily temperatures are above 0 degc and minimum daily temperatures are at or below 0 degc for at least 1 consecutive day(s). [days]`

`atmos.freezethaw_spell_mean_length`

:**Freeze-thaw spell mean length**-
**Description:**Average length of daily freeze-thaw spells. A freeze-thaw spell is defined as a number of consecutive days where maximum daily temperatures are above a given threshold and minimum daily temperatures are at or below a given threshold, usually 0°C for both.

**Based on**`xclim.indices.multiday_temperature_swing`

**Produces:**`freezethaw_spell_mean_length: Average length of events where maximum daily temperatures are above 0 degc and minimum daily temperatures are at or below 0 degc for at least 1 consecutive day(s). [days]`

`atmos.freezing_degree_days`

:**Freezing degree days**-
**Description:**The cumulative degree days for days when the average temperature is below a given threshold, typically 0°C.

**Based on**`xclim.indices.heating_degree_days`

**Produces:**`freezing_degree_days: Cumulative sum of temperature degrees for mean daily temperature below 0 degc [K days]`

`atmos.freshet_start`

:**Day of year of spring freshet start**-
**Description:**Day of year of the spring freshet start, defined as the first day when the temperature exceeds a certain threshold for a given number of consecutive days.

**Based on**`xclim.indices.first_day_temperature_above`

**Produces:**`freshet_start: First day where temperature threshold of 0 degc is exceeded for at least 5 days []`

`atmos.frost_days`

:**Frost days**-
**Description:**Number of days where the daily minimum temperature is below a given threshold.

**Based on**`xclim.indices.frost_days`

**Produces:**`frost_days: Number of days where the daily minimum temperature is below 0 degc [days]`

`atmos.frost_free_season_end`

:**Frost free season end**-
**Description:**First day when the temperature is below a given threshold for a given number of consecutive days after a median calendar date.

**Based on**`xclim.indices.frost_free_season_end`

**Produces:**`frost_free_season_end: First day, after 07-01, following a period of 5 days with minimum daily temperature below 0 degc []`

`atmos.frost_free_season_length`

:**Frost free season length**-
**Description:**Duration of the frost free season, defined as the period when the minimum daily temperature is above 0°C without a freezing window of `N` days, with freezing occurring after a median calendar date.

**Based on**`xclim.indices.frost_free_season_length`

**Produces:**`frost_free_season_length: Number of days between the first occurrence of at least 5 consecutive days with minimum daily temperature at or above 0 degc and the first occurrence of at least 5 consecutive days with minimum daily temperature below 0 degc after 07-01 [days]`

`atmos.frost_free_season_start`

:**Frost free season start**-
**Description:**First day when minimum daily temperature exceeds a given threshold for a given number of consecutive days

**Based on**`xclim.indices.frost_free_season_start`

**Produces:**`frost_free_season_start: First day following a period of 5 days with minimum daily temperature at or above 0 degc []`

`atmos.frost_season_length`

:**Frost season length**-
**Description:**Duration of the freezing season, defined as the period when the daily minimum temperature is below 0°C without a thawing window of days, with the thaw occurring after a median calendar date.

**Based on**`xclim.indices.frost_season_length`

**Produces:**`frost_season_length: Number of days between the first occurrence of at least 5 consecutive days with minimum daily temperature below 0 degc and the first occurrence of at least 5 consecutive days with minimum daily temperature at or above 0 degc after 01-01 [days]`

`atmos.griffiths_drought_factor`

:**Griffiths drought factor based on the soil moisture deficit.**-
**Id:**df

**Description:**The drought factor is a numeric indicator of the forest fire fuel availability in the deep litter bed. It is often used in the calculation of the McArthur Forest Fire Danger Index. The method implemented here follows :cite:t:`ffdi-finkele_2006`.

**Based on**`xclim.indices.griffiths_drought_factor`

**Produces:**`df: Griffiths drought factor []`

`atmos.growing_degree_days`

:**Growing degree days**-
**Description:**The cumulative degree days for days when the average temperature is above a given threshold.

**Based on**`xclim.indices.growing_degree_days`

**Produces:**`growing_degree_days: Cumulative sum of temperature degrees for mean daily temperature above 4.0 degc [K days]`

`atmos.growing_season_end`

:**Growing season end**-
**Description:**The first day when the temperature is below a certain threshold for a certain number of consecutive days after a given calendar date.

**Based on**`xclim.indices.growing_season_end`

**Produces:**`growing_season_end: First day of the first series of 5 days with mean daily temperature below 5.0 degc, occurring after 07-01 []`

`atmos.growing_season_length`

:**Growing season length**-
**Description:**Number of days between the first occurrence of a series of days with a daily average temperature above a threshold and the first occurrence of a series of days with a daily average temperature below that same threshold, occurring after a given calendar date.

**Based on**`xclim.indices.growing_season_length`

**Produces:**`growing_season_length: Number of days between the first occurrence of at least 6 consecutive days with mean daily temperature over 5.0 degc and the first occurrence of at least 6 consecutive days with mean daily temperature below 5.0 degc, occurring after 07-01 [days]`

`atmos.growing_season_start`

:**Growing season start**-
**Description:**The first day when the temperature exceeds a certain threshold for a given number of consecutive days.

**Based on**`xclim.indices.growing_season_start`

**Produces:**`growing_season_start: First day of the first series of 5 days with mean daily temperature above or equal to 5.0 degc []`

`atmos.heat_index`

:**Heat index**-
**Description:**The heat index is an estimate of the temperature felt by a person in the shade when relative humidity is taken into account.

**Based on**`xclim.indices.heat_index`

**Produces:**`heat_index: Heat index [C]`

`atmos.heat_wave_frequency`

:**Heat wave frequency**-
**Description:**Number of heat waves. A heat wave occurs when daily minimum and maximum temperatures exceed given thresholds for a number of days.

**Based on**`xclim.indices.heat_wave_frequency`

**Produces:**`heat_wave_frequency: Total number of series of at least 3 consecutive days with daily minimum temperature above 22.0 degc and daily maximum temperature above 30 degc []`

`atmos.heat_wave_index`

:**Heat wave index**-
**Description:**Number of days that constitute heatwave events. A heat wave occurs when daily minimum and maximum temperatures exceed given thresholds for a number of days.

**Based on**`xclim.indices.heat_wave_index`

**Produces:**`heat_wave_index: Total number of days constituting events of at least 5 consecutive days with daily maximum temperature above 25.0 degc [days]`

`atmos.heat_wave_max_length`

:**Heat wave maximum length**-
**Description:**Total duration of heat waves. A heat wave occurs when daily minimum and maximum temperatures exceed given thresholds for a number of days.

**Based on**`xclim.indices.heat_wave_max_length`

**Produces:**`heat_wave_max_length: Longest series of at least 3 consecutive days with daily minimum temperature above 22.0 degc and daily maximum temperature above 30 degc [days]`

`atmos.heat_wave_total_length`

:**Heat wave total length**-
**Description:**Maximum length of heat waves. A heat wave occurs when daily minimum and maximum temperatures exceed given thresholds for a number of days.

**Based on**`xclim.indices.heat_wave_total_length`

**Produces:**`heat_wave_total_length: Total length of events of at least 3 consecutive days with daily minimum temperature above 22.0 degc and daily maximum temperature above 30 degc [days]`

`atmos.heating_degree_days`

:**Heating degree days**-
**Description:**The cumulative degree days for days when the mean daily temperature is below a given threshold and buildings must be heated.

**Based on**`xclim.indices.heating_degree_days`

**Produces:**`heating_degree_days: Cumulative sum of temperature degrees for mean daily temperature below 17.0 degc [K days]`

`atmos.high_precip_low_temp`

:**Days with precipitation and cold temperature**-
**Description:**Number of days with precipitation above a given threshold and temperature below a given threshold.

**Based on**`xclim.indices.high_precip_low_temp`

**Produces:**`high_precip_low_temp: Days with precipitation at or above 0.4 mm/d and temperature below -0.2 degc [days]`

`atmos.hot_spell_frequency`

:**Hot spell frequency**-
**Description:**Number of hot spells events within a given period. A hot spell occurs when the daily maximum temperatureexceeds a given threshold for a minimum number of days.

**Based on**`xclim.indices.hot_spell_frequency`

**Produces:**`hot_spell_frequency: Total number of series of at least 3 consecutive days with daily maximum temperature above 30 degc []`

`atmos.hot_spell_max_length`

:**Hot spell maximum length**-
**Description:**Maximum length of hot spells events within a given period. A hot spell occurs when the daily maximum temperature exceeds a given threshold for a minimum number of days.

**Based on**`xclim.indices.hot_spell_max_length`

**Produces:**`hot_spell_max_length: Longest series of at least 1 consecutive days with daily maximum temperature above 30 degc [days]`

`atmos.huglin_index`

:**Huglin heliothermal index**-
**Description:**Heat-summation index for agroclimatic suitability estimation, developed specifically for viticulture. Considers daily minimum and maximum temperature with a given base threshold, typically between 1 April and 30September, and integrates a day-length coefficient calculation for higher latitudes. Metric originally published in Huglin (1978). Day-length coefficient based on Hall & Jones (2010).

**Based on**`xclim.indices.huglin_index`

**Produces:**`hi: Integral of mean daily temperature above 10 degc multiplied by day-length coefficient with jones method for days between 04-01 and 10-01 []`

`atmos.humidex`

:**Humidex**-
**Description:**The humidex describes the temperature felt by a person when relative humidity is taken into account. It can be interpreted as the equivalent temperature felt when the air is dry.

**Based on**`xclim.indices.humidex`

**Produces:**`humidex: Humidex index [C]`

`atmos.ice_days`

:**Ice days**-
**Description:**Number of days where the daily maximum temperature is below 0°C

**Based on**`xclim.indices.ice_days`

**Produces:**`ice_days: Number of days with maximum daily temperature below 0 degc [days]`

`atmos.jetstream_metric_woollings`

:**Strength and latitude of jetstream**-
**Description:**Identify latitude and strength of maximum smoothed zonal wind speed in the region from 15 to 75°N and -60 to 0°E, using the formula outlined in :cite:p:`woollings_variability_2010`. Wind is smoothened using a Lanczos filter approach.

**Based on**`xclim.indices.jetstream_metric_woollings`

**Produces:**`jetlat: Latitude of maximum smoothed zonal wind speed [degrees_North]`

`jetstr: Maximum strength of smoothed zonal wind speed [m s-1]`

`atmos.keetch_byram_drought_index`

:**Keetch-Byram drought index (KBDI) for soil moisture deficit.**-
**Id:**kbdi

**Description:**The KBDI indicates the amount of water necessary to bring the soil moisture content back to field capacity. It is often used in the calculation of the McArthur Forest Fire Danger Index. The method implemented here follows :cite:t:`ffdi-finkele_2006` but limits the maximum KBDI to 203.2 mm, rather than 200 mm, in order to align best with the majority of the literature.

**Based on**`xclim.indices.keetch_byram_drought_index`

**Produces:**`kbdi: Keetch-byran drought index [mm/day]`

`atmos.last_snowfall`

:**Last day where solid precipitation flux exceeded a given threshold**-
**Description:**The last day where the solid precipitation flux exceeded a given threshold during a time period.

**Based on**`xclim.indices.last_snowfall`

**Produces:**`last_snowfall: Date of last day where the solid precipitation flux exceeded 0.5 mm/day []`

`atmos.last_spring_frost`

:**Last spring frost**-
**Description:**The last day when temperature is below a given threshold for a certain number of days, limited by a final calendar date.

**Based on**`xclim.indices.last_spring_frost`

**Produces:**`last_spring_frost: Last day of minimum daily temperature below a threshold of 0 degc for at least 1 days before a given date (07-01) []`

`atmos.latitude_temperature_index`

:**Latitude temperature index**-
**Description:**A climate indice based on mean temperature of the warmest month and a latitude-based coefficient to account for longer day-length favouring growing conditions. Developed specifically for viticulture. Mean temperature of warmest month multiplied by the difference of latitude factor coefficient minus latitude. Metric originally published in Jackson, D. I., & Cherry, N. J. (1988).

**Based on**`xclim.indices.latitude_temperature_index`

**Produces:**`lti: Mean temperature of warmest month multiplied by the difference of 60 minus latitude []`

`atmos.liquid_precip_accumulation`

:**Total accumulated liquid precipitation.**-
**Id:**liquidprcptot

**Description:**Total accumulated liquid precipitation. Precipitation is considered liquid when the average daily temperature is above 0°C.

**Based on**`xclim.indices.precip_accumulation`

**Produces:**`liquidprcptot: Total accumulated precipitation when temperature is above 0 degc [mm]`

`atmos.liquid_precip_ratio`

:**Fraction of liquid to total precipitation**-
**Description:**The ratio of total liquid precipitation over the total precipitation. Liquid precipitation is approximated from total precipitation on days where temperature is above a given threshold.

**Based on**`xclim.indices.liquid_precip_ratio`

**Produces:**`liquid_precip_ratio: Fraction of liquid to total precipitation (temperature above 0 degc) []`

`atmos.max_1day_precipitation_amount`

:**Maximum 1-day total precipitation**-
**Id:**rx1day

**Description:**Maximum total daily precipitation for a given period.

**Based on**`xclim.indices.max_1day_precipitation_amount`

**Produces:**`rx1day: Maximum 1-day total precipitation [mm/day]`

`atmos.max_daily_temperature_range`

:**Maximum of daily temperature range**-
**Id:**dtrmax

**Description:**The maximum difference between the daily maximum and minimum temperatures.

**Based on**`xclim.indices.daily_temperature_range`

**Produces:**`dtrmax: Maximum diurnal temperature range [K]`

`atmos.max_n_day_precipitation_amount`

:**maximum n-day total precipitation**-
**Description:**Maximum of the moving sum of daily precipitation for a given period.

**Based on**`xclim.indices.max_n_day_precipitation_amount`

**Produces:**`rx1day: Maximum 1-day total precipitation amount [mm]`

`atmos.max_pr_intensity`

:**Maximum precipitation intensity over time window**-
**Description:**Maximum precipitation intensity over a given rolling time window.

**Based on**`xclim.indices.max_pr_intensity`

**Produces:**`max_pr_intensity: Maximum precipitation intensity over rolling 1h time window [mm h-1]`

`atmos.maximum_consecutive_dry_days`

:**Maximum consecutive dry days**-
**Id:**cdd

**Description:**The longest number of consecutive days where daily precipitation below a given threshold.

**Based on**`xclim.indices.maximum_consecutive_dry_days`

**Produces:**`cdd: Maximum consecutive days with daily precipitation below 1 mm/day [days]`

`atmos.maximum_consecutive_frost_free_days`

:**Maximum consecutive frost free days**-
**Id:**consecutive_frost_free_days

**Description:**Maximum number of consecutive frost-free days: where the daily minimum temperature is above or equal to 0°C

**Based on**`xclim.indices.maximum_consecutive_frost_free_days`

**Produces:**`consecutive_frost_free_days: Maximum number of consecutive days with minimum temperature at or above 0 degc [days]`

`atmos.maximum_consecutive_warm_days`

:**Maximum consecutive warm days**-
**Description:**Maximum number of consecutive days where the maximum daily temperature exceeds a certain threshold.

**Based on**`xclim.indices.maximum_consecutive_tx_days`

**Produces:**`maximum_consecutive_warm_days: Maximum number of consecutive days with maximum daily temperature above 25 degc [days]`

`atmos.maximum_consecutive_wet_days`

:**Maximum consecutive wet days**-
**Id:**cwd

**Description:**The longest number of consecutive days where daily precipitation is at or above a given threshold.

**Based on**`xclim.indices.maximum_consecutive_wet_days`

**Produces:**`cwd: Maximum consecutive days with daily precipitation at or above 1 mm/day [days]`

`atmos.mcarthur_forest_fire_danger_index`

:**McArthur forest fire danger index (FFDI) Mark 5.**-
**Id:**ffdi

**Description:**The FFDI is a numeric indicator of the potential danger of a forest fire.

**Based on**`xclim.indices.mcarthur_forest_fire_danger_index`

**Produces:**`ffdi: Mcarthur forest fire danger index []`

`atmos.mean_radiant_temperature`

:**Mean radiant temperature**-
**Description:**The average temperature of solar and thermal radiation incident on the body's exterior.

**Based on**`xclim.indices.mean_radiant_temperature`

**Produces:**`mrt: Mean radiant temperature [K]`

`atmos.potential_evapotranspiration`

:**Potential evapotranspiration**-
**Description:**The potential for water evaporation from soil and transpiration by plants if the water supply is sufficient, calculated with a given method.

**Based on**`xclim.indices.potential_evapotranspiration`

**Produces:**`evspsblpot: Potential evapotranspiration ("br65" method) [kg m-2 s-1]`

`atmos.precip_accumulation`

:**Total accumulated precipitation (solid and liquid)**-
**Id:**prcptot

**Description:**Total accumulated precipitation. If the average daily temperature is given, the phase parameter can be used to restrict the calculation to precipitation of only one phase (liquid or solid). Precipitation is considered solid if the average daily temperature is below 0°C (and vice versa).

**Based on**`xclim.indices.precip_accumulation`

**Produces:**`prcptot: Total accumulated precipitation [mm]`

`atmos.rain_approximation`

:**Rainfall approximation**-
**Id:**prlp

**Description:**Liquid precipitation estimated from total precipitation and temperature with a given method and temperature threshold.

**Based on**`xclim.indices.rain_approximation`

**Produces:**`prlp: Liquid precipitation ("binary" method with temperature at or above 0 degc) [kg m-2 s-1]`

`atmos.rain_on_frozen_ground_days`

:**Number of rain on frozen ground days**-
**Id:**rain_frzgr

**Description:**The number of days with rain above a given threshold after a series of seven days with average daily temperature below 0°C. Precipitation is assumed to be rain when the daily average temperature is above 0°C.

**Based on**`xclim.indices.rain_on_frozen_ground_days`

**Produces:**`rain_frzgr: Number of rain on frozen ground days (mean daily temperature > 0℃ and precipitation > 1 mm/d) [days]`

`atmos.relative_humidity`

:**Relative humidity from temperature, specific humidity, and pressure**-
**Id:**hurs

**Description:**Calculation of relative humidity from temperature, specific humidity, and pressure using the saturation vapour pressure.

**Based on**`xclim.indices.relative_humidity`

**Produces:**`hurs: Relative humidity ("sonntag90" method) [%]`

`atmos.relative_humidity_from_dewpoint`

:**Relative humidity from temperature and dewpoint temperature**-
**Id:**hurs_fromdewpoint

**Description:**Calculation of relative humidity from temperature and dew point using the saturation vapour pressure.

**Based on**`xclim.indices.relative_humidity`

**Produces:**`hurs: Relative humidity ("sonntag90" method) [%]`

`atmos.rprctot`

:**Proportion of accumulated precipitation arising from convective processes**-
**Description:**The proportion of total precipitation due to convective processes. Only days with surpassing a minimum precipitation flux are considered.

**Based on**`xclim.indices.rprctot`

**Produces:**`rprctot: Proportion of accumulated precipitation arising from convective processeswith precipitation of at least 1.0 mm/day []`

`atmos.saturation_vapor_pressure`

:**Saturation vapour pressure (e_sat)**-
**Id:**e_sat

**Description:**Calculation of the saturation vapour pressure from the temperature, according to a given method. If ice_thresh is given, the calculation is done with reference to ice for temperatures below this threshold.

**Based on**`xclim.indices.saturation_vapor_pressure`

**Produces:**`e_sat: Saturation vapour pressure ("sonntag90" method) [Pa]`

`atmos.snowfall_approximation`

:**Snowfall approximation**-
**Id:**prsn

**Description:**Solid precipitation estimated from total precipitation and temperature with a given method and temperature threshold.

**Based on**`xclim.indices.snowfall_approximation`

**Produces:**`prsn: Solid precipitation ("binary" method with temperature at or below 0 degc) [kg m-2 s-1]`

`atmos.solid_precip_accumulation`

:**Total accumulated solid precipitation.**-
**Id:**solidprcptot

**Description:**Total accumulated solid precipitation. Precipitation is considered solid when the average daily temperature is at or below 0°C.

**Based on**`xclim.indices.precip_accumulation`

**Produces:**`solidprcptot: Total accumulated solid precipitation [mm]`

`atmos.specific_humidity`

:**Specific humidity from temperature, relative humidity, and pressure**-
**Id:**huss

**Description:**Calculation of specific humidity from temperature, relative humidity, and pressure using the saturation vapour pressure.

**Based on**`xclim.indices.specific_humidity`

**Produces:**`huss: Specific humidity ("sonntag90" method) []`

`atmos.specific_humidity_from_dewpoint`

:**Specific humidity from dew point temperature and pressure**-
**Id:**huss_fromdewpoint

**Description:**Calculation of the specific humidity from dew point temperature and pressure using the saturation vapour pressure.

**Based on**`xclim.indices.specific_humidity_from_dewpoint`

**Produces:**`huss_fromdewpoint: Specific humidity ("sonntag90" method) []`

`atmos.standardized_precipitation_evapotranspiration_index`

:**Standardized Precipitation Evapotranspiration Index (SPEI)**-
**Id:**spei

**Description:**Water budget (precipitation - evapotranspiration) over a moving window, normalized such that the SPEI averages to 0 for the calibration data. The window unit `X` is the minimal time period defined by the resampling frequency.

**Based on**`xclim.indices.standardized_precipitation_evapotranspiration_index`

**Produces:**`spei: Standardized precipitation evapotranspiration index (spei) []`

`atmos.standardized_precipitation_index`

:**Standardized Precipitation Index (SPI)**-
**Id:**spi

**Description:**Precipitation over a moving window, normalized such that SPI averages to 0 for the calibration data. The window unit `X` is the minimal time period defined by the resampling frequency.

**Based on**`xclim.indices.standardized_precipitation_index`

**Produces:**`spi: Standardized precipitation index (spi) []`

`atmos.tg`

:**Mean temperature**-
**Description:**The average daily temperature assuming a symmetrical temperature distribution (Tg = (Tx + Tn) / 2).

**Based on**`xclim.indices.tas`

**Produces:**`tg: Daily mean temperature [K]`

`atmos.tg10p`

:**Days with mean temperature below the 10th percentile**-
**Description:**Number of days with mean temperature below the 10th percentile.

**Based on**`xclim.indices.tg10p`

**Produces:**`tg10p: Number of days with mean temperature below the 10th percentile [days]`

`atmos.tg90p`

:**Days with mean temperature above the 90th percentile**-
**Description:**Number of days with mean temperature above the 90th percentile.

**Based on**`xclim.indices.tg90p`

**Produces:**`tg90p: Number of days with mean temperature above the 90th percentile [days]`

`atmos.tg_days_above`

:**Number of days with mean temperature above a given threshold**-
**Description:**The number of days with mean temperature above a given threshold.

**Based on**`xclim.indices.tg_days_above`

**Produces:**`tg_days_above: The number of days with mean temperature above 10.0 degc [days]`

`atmos.tg_days_below`

:**Number of days with mean temperature below a given threshold**-
**Description:**The number of days with mean temperature below a given threshold.

**Based on**`xclim.indices.tg_days_below`

**Produces:**`tg_days_below: The number of days with mean temperature below 10.0 degc [days]`

`atmos.tg_max`

:**Maximum of mean temperature**-
**Description:**Maximum of daily mean temperature.

**Based on**`xclim.indices.tg_max`

**Produces:**`tg_max: Maximum daily mean temperature [K]`

`atmos.tg_mean`

:**Mean temperature**-
**Description:**Mean of daily mean temperature.

**Based on**`xclim.indices.tg_mean`

**Produces:**`tg_mean: Mean daily mean temperature [K]`

`atmos.tg_min`

:**Minimum of mean temperature**-
**Description:**Minimum of daily mean temperature.

**Based on**`xclim.indices.tg_min`

**Produces:**`tg_min: Minimum daily mean temperature [K]`

`atmos.thawing_degree_days`

:**Thawing degree days**-
**Description:**The cumulative degree days for days when the average temperature is above a given threshold, typically 0°C.

**Based on**`xclim.indices.growing_degree_days`

**Produces:**`thawing_degree_days: Cumulative sum of temperature degrees for mean daily temperature above 0 degc [K days]`

`atmos.tn10p`

:**Days with minimum temperature below the 10th percentile**-
**Description:**Number of days with minimum temperature below the 10th percentile.

**Based on**`xclim.indices.tn10p`

**Produces:**`tn10p: Number of days with minimum temperature below the 10th percentile [days]`

`atmos.tn90p`

:**Days with minimum temperature above the 90th percentile**-
**Description:**Number of days with minimum temperature above the 90th percentile.

**Based on**`xclim.indices.tn90p`

**Produces:**`tn90p: Number of days with minimum temperature above the 90th percentile [days]`

`atmos.tn_days_above`

:**Number of days with minimum temperature above a given threshold**-
**Description:**The number of days with minimum temperature above a given threshold.

**Based on**`xclim.indices.tn_days_above`

**Produces:**`tn_days_above: The number of days with minimum temperature above 20.0 degc [days]`

`atmos.tn_days_below`

:**Number of days with minimum temperature below a given threshold**-
**Description:**The number of days with minimum temperature below a given threshold.

**Based on**`xclim.indices.tn_days_below`

**Produces:**`tn_days_below: The number of days with minimum temperature below -10.0 degc [days]`

`atmos.tn_max`

:**Maximum of minimum temperature**-
**Description:**Maximum of daily minimum temperature.

**Based on**`xclim.indices.tn_max`

**Produces:**`tn_max: Maximum daily minimum temperature [K]`

`atmos.tn_mean`

:**Mean of minimum temperature**-
**Description:**Mean of daily minimum temperature.

**Based on**`xclim.indices.tn_mean`

**Produces:**`tn_mean: Mean daily minimum temperature [K]`

`atmos.tn_min`

:**Minimum temperature**-
**Description:**Minimum of daily minimum temperature.

**Based on**`xclim.indices.tn_min`

**Produces:**`tn_min: Minimum daily minimum temperature [K]`

`atmos.tropical_nights`

:**Tropical nights**-
**Description:**Number of days where minimum temperature is above a given threshold.

**Based on**`xclim.indices.tn_days_above`

**Produces:**`tropical_nights: Number of days with minimum daily temperature above 20.0 degc [days]`

`atmos.tx10p`

:**Days with maximum temperature below the 10th percentile**-
**Description:**Number of days with maximum temperature below the 10th percentile.

**Based on**`xclim.indices.tx10p`

**Produces:**`tx10p: Number of days with maximum temperature below the 10th percentile [days]`

`atmos.tx90p`

:**Days with maximum temperature above the 90th percentile**-
**Description:**Number of days with maximum temperature above the 90th percentile.

**Based on**`xclim.indices.tx90p`

**Produces:**`tx90p: Number of days with maximum temperature above the 90th percentile [days]`

`atmos.tx_days_above`

:**Number of days with maximum temperature above a given threshold**-
**Description:**The number of days with maximum temperature above a given threshold.

**Based on**`xclim.indices.tx_days_above`

**Produces:**`tx_days_above: The number of days with maximum temperature above 25.0 degc [days]`

`atmos.tx_days_below`

:**Number of days with maximum temperature below a given threshold**-
**Description:**The number of days with maximum temperature below a given threshold.

**Based on**`xclim.indices.tx_days_below`

**Produces:**`tx_days_below: The number of days with maximum temperature below 25.0 degc [days]`

`atmos.tx_max`

:**Maximum temperature**-
**Description:**Maximum of daily maximum temperature.

**Based on**`xclim.indices.tx_max`

**Produces:**`tx_max: Maximum daily maximum temperature [K]`

`atmos.tx_mean`

:**Mean of maximum temperature**-
**Description:**Mean of daily maximum temperature.

**Based on**`xclim.indices.tx_mean`

**Produces:**`tx_mean: Mean daily maximum temperature [K]`

`atmos.tx_min`

:**Minimum of maximum temperature**-
**Description:**Minimum of daily maximum temperature.

**Based on**`xclim.indices.tx_min`

**Produces:**`tx_min: Minimum daily maximum temperature [K]`

`atmos.tx_tn_days_above`

:**Number of days with daily minimum and maximum temperatures exceeding thresholds**-
**Description:**Number of days with daily maximum and minimum temperatures above given thresholds.

**Based on**`xclim.indices.tx_tn_days_above`

**Produces:**`tx_tn_days_above: Number of days with daily minimum above 22 degc and daily maximum temperatures above 30 degc [days]`

`atmos.universal_thermal_climate_index`

:**Universal Thermal Climate Index (UTCI)**-
**Id:**utci

**Description:**UTCI is the equivalent temperature for the environment derived from a reference environment and is used to evaluate heat stress in outdoor spaces.

**Based on**`xclim.indices.universal_thermal_climate_index`

**Produces:**`utci: Universal thermal climate index (utci) [K]`

`atmos.warm_and_dry_days`

:**Warm and dry days**-
**Description:**Number of days with temperature above a given percentile and precipitation below a given percentile.

**Based on**`xclim.indices.warm_and_dry_days`

**Produces:**`warm_and_dry_days: Number of days where temperature is above {unknown}th percentile and precipitation is below {unknown}th percentile [days]`

`atmos.warm_and_wet_days`

:**Warm and wet days**-
**Description:**Number of days with temperature above a given percentile and precipitation above a given percentile.

**Based on**`xclim.indices.warm_and_wet_days`

**Produces:**`warm_and_wet_days: Number of days where temperature above {unknown}th percentile and precipitation above {unknown}th percentile [days]`

`atmos.warm_spell_duration_index`

:**Warm spell duration index**-
**Description:**Number of days part of a percentile-defined warm spell. A warm spell occurs when the maximum daily temperature is above a given percentile for a given number of consecutive days.

**Based on**`xclim.indices.warm_spell_duration_index`

**Produces:**`warm_spell_duration_index: Number of days with at least 6 consecutive days where the maximum daily temperature is above the {unknown}th percentile(s) [days]`

`atmos.water_budget`

:**Water budget**-
**Description:**Precipitation minus potential evapotranspiration as a measure of an approximated surface water budget.

**Based on**`xclim.indices.water_budget`

**Produces:**`water_budget: Water budget [kg m-2 s-1]`

`atmos.water_budget_from_tas`

:**Water budget**-
**Description:**Precipitation minus potential evapotranspiration as a measure of an approximated surface water budget, where the potential evapotranspiration is calculated with a given method.

**Based on**`xclim.indices.water_budget`

**Produces:**`water_budget_from_tas: Water budget ("br65" method) [kg m-2 s-1]`

`atmos.wet_precip_accumulation`

:**Total accumulated precipitation (solid and liquid) during wet days**-
**Id:**wet_prcptot

**Description:**Total accumulated precipitation on days with precipitation. A day is considered to have precipitation if the precipitation is greater than or equal to a given threshold.

**Based on**`xclim.indices.prcptot`

**Produces:**`wet_prcptot: Total accumulated precipitation over days where precipitation exceeds 1 mm/day [mm]`

`atmos.wetdays`

:**Number of wet days**-
**Description:**The number of days with daily precipitation at or above a given threshold.

**Based on**`xclim.indices.wetdays`

**Produces:**`wetdays: Number of days with daily precipitation at or above 1.0 mm/day [days]`

`atmos.wetdays_prop`

:**Proportion of wet days**-
**Description:**The proportion of days with daily precipitation at or above a given threshold.

**Based on**`xclim.indices.wetdays_prop`

**Produces:**`wetdays_prop: Proportion of days with precipitation at or above 1.0 mm/day [1]`

`atmos.wind_chill_index`

:**Wind chill**-
**Id:**wind_chill

**Description:**Wind chill factor is an index that equates to how cold an average person feels. It is calculated from the temperature and the wind speed at 10 m. As defined by Environment and Climate Change Canada, a second formula is used for light winds. The standard formula is otherwise the same as used in the United States.

**Based on**`xclim.indices.wind_chill_index`

**Produces:**`wind_chill: Wind chill factor [degC]`

`atmos.wind_speed_from_vector`

:**Wind speed and direction from vector**-
**Description:**Calculation of the magnitude and direction of the wind speed from the two components west-east and south-north.

**Based on**`xclim.indices.uas_vas_2_sfcwind`

**Produces:**`sfcWind: Near-surface wind speed [m s-1]`

`sfcWindfromdir: Near-surface wind from direction [degree]`

`atmos.wind_vector_from_speed`

:**Wind vector from speed and direction**-
**Description:**Calculation of the two components (west-east and north-south) of the wind from the magnitude of its speed and direction of origin.

**Based on**`xclim.indices.sfcwind_2_uas_vas`

**Produces:**`uas: Near-surface eastward wind [m s-1]`

`vas: Near-surface northward wind [m s-1]`

`atmos.windy_days`

:**Windy days**-
**Description:**Number of days with surface wind speed at or above threshold.

**Based on**`xclim.indices.windy_days`

**Produces:**`windy_days: Number of days with surface wind speed at or above 10.8 m s-1 [days]`

## land: Land surface

`land.base_flow_index`

:**Base flow index**-
**Description:**Return the base flow index, defined as the minimum 7-day average flow divided by the mean flow.

**Based on**`xclim.indices.base_flow_index`

**Produces:**`base_flow_index: Base flow index []`

`land.blowing_snow`

:**Blowing snow days**-
**Description:**The number of days with snowfall, snow depth, and windspeed over given thresholds for a period of days.

**Based on**`xclim.indices.blowing_snow`

**Produces:**`annual_blowing_snow: Days with snowfall and wind speed at or above given thresholds [days]`

`land.continuous_snow_cover_end`

:**End date of continuous snow cover**-
**Description:**The first date on which snow depth is below a given threshold for a given number of consecutive days.

**Based on**`xclim.indices.continuous_snow_cover_end`

**Produces:**`continuous_snow_cover_end: End date of continuous snow cover []`

`land.continuous_snow_cover_start`

:**Start date of continuous snow cover**-
**Description:**The first date on which snow depth is greater than or equal to a given threshold for a given number of consecutive days.

**Based on**`xclim.indices.continuous_snow_cover_start`

**Produces:**`continuous_snow_cover_start: Start date of continuous snow cover []`

`land.doy_qmax`

:**Day of year of the maximum streamflow**-
**Description:**

**Based on**`xclim.indices.generic.select_resample_op`

**Produces:**`qannual_doy_qmax: Day of the year of the maximum streamflow over annual []`

`land.doy_qmin`

:**Day of year of the minimum streamflow**-
**Description:**

**Based on**`xclim.indices.generic.select_resample_op`

**Produces:**`qannual_doy_qmin: Day of the year of the minimum streamflow over annual []`

`land.fit`

:**Distribution parameters fitted over the time dimension.**-
**Id:**discharge_distribution_fit

**Description:**

**Based on**`xclim.indices.fit`

**Produces:**`params: Normal distribution parameters []`

`land.freq_analysis`

:**Return level**-
**Description:**Streamflow frequency analysis on the basis of a given mode and distribution.

**Based on**`xclim.indices.frequency_analysis`

**Produces:**`q1`

annual: N-year return level discharge [m^3 s-1] `land.rb_flashiness_index`

:**Richards-Baker Flashiness Index**-
**Description:**Measurement of flow oscillations relative to average flow, quantifying the frequency and speed of flow changes.

**Based on**`xclim.indices.rb_flashiness_index`

**Produces:**`rbi: Richards-baker flashiness index []`

`land.snd_max_doy`

:**Day of year of maximum snow depth**-
**Description:**Day of the year when snow depth reaches its maximum value.

**Based on**`xclim.indices.snd_max_doy`

**Produces:**`annual_snd_max_doy: Day of the year when snow depth reaches its maximum value []`

`land.snow_cover_duration`

:**Snow cover duration**-
**Description:**Number of days when the snow depth is greater than or equal to a given threshold.

**Based on**`xclim.indices.snow_cover_duration`

**Produces:**`snow_cover_duration: Number of days with snow depth at or above threshold [days]`

`land.snow_depth`

:**Mean snow depth**-
**Description:**Mean of daily snow depth.

**Based on**`xclim.indices.snow_depth`

**Produces:**`snow_depth: Mean of daily snow depth [cm]`

`land.snow_melt_we_max`

:**Maximum snow melt**-
**Description:**The water equivalent of the maximum snow melt.

**Based on**`xclim.indices.snow_melt_we_max`

**Produces:**`annual_snow_melt_we_max: Maximum snow melt [kg m-2]`

`land.snw_max`

:**Maximum snow amount**-
**Description:**The maximum snow water equivalent amount on the surface.

**Based on**`xclim.indices.snw_max`

**Produces:**`annual_snw_max: Maximum snow water equivalent amount [kg m-2]`

`land.snw_max_doy`

:**Day of year of maximum snow amount**-
**Description:**The day of year when snow water equivalent amount on the surface reaches its maximum.

**Based on**`xclim.indices.snw_max_doy`

**Produces:**`annual_snw_max_doy: Day of year of maximum daily snow water equivalent amount []`

`land.stats`

:**Statistic of the daily flow for a given period.**-
**Id:**discharge_stats

**Description:**

**Based on**`xclim.indices.generic.select_resample_op`

**Produces:**`qannual`

: Daily flow statistics [m^3 s-1] `land.winter_storm`

:**Winter storm days**-
**Description:**Number of days with snowfall accumulation greater or equal to threshold (default: 25 cm).

**Based on**`xclim.indices.winter_storm`

**Produces:**`annual_winter_storm: Days with snowfall at or above a given threshold [days]`

## seaIce: Sea ice

`seaIce.sea_ice_area`

:**Sea ice area**-
**Description:**A measure of total ocean surface covered by sea ice.

**Based on**`xclim.indices.sea_ice_area`

**Produces:**`sea_ice_area: Sum of ice-covered areas where sea ice concentration exceeds 15 pct [m2]`

`seaIce.sea_ice_extent`

:**Sea ice extent**-
**Description:**A measure of the extent of all areas where sea ice concentration exceeds a threshold.

**Based on**`xclim.indices.sea_ice_extent`

**Produces:**`sea_ice_extent: Sum of ocean areas where sea ice concentration exceeds 15 pct [m2]`

## Virtual submodules

### CF Standard indices

Indicators found here are defined by the team at clix-meta. Adapted documentation from that repository follows:

The repository aims to provide a platform for thinking about, and developing, a unified view of metadata elements required to describe climate indices (aka climate indicators).

To facilitate data exchange and dissemination the metadata should, as far as possible, follow the Climate and Forecasting (CF) Conventions. Considering the very rich and diverse flora of climate indices, this is however not always possible. By collecting a wide range of different indices it is easier to discover any common patterns and features that are currently not well covered by the CF Conventions. Currently identified issues frequently relate to standard_name and/or cell_methods which both are controlled vocabularies of the CF Conventions.

`cf.cdd`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`cdd: Maximum consecutive dry days (precip < 1mm) [day]`

`cf.cddcoldTT`

:**Calculate the temperature sum above/below a threshold.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Finally, the sum is calculated for those data values that fulfill the condition after subtraction of the threshold value. If the sum is for values below the threshold the result is multiplied by -1.

**Based on**`xclim.indices.generic.temperature_sum`

**Produces:**`cddcold`

: Cooling degree days (tmean > c) [degree_Celsius day] `cf.cfd`

:**Calculate the number of times some condition is met.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is `<`, then this counts the number of times `data < threshold`. Finally, count the number of occurrences when condition is met.

**Based on**`xclim.indices.generic.count_occurrences`

**Produces:**`cfd: Maximum number of consecutive frost days (tmin < 0 c) [day]`

`cf.csu`

:**Calculate the number of times some condition is met.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is `<`, then this counts the number of times `data < threshold`. Finally, count the number of occurrences when condition is met.

**Based on**`xclim.indices.generic.count_occurrences`

**Produces:**`csu: Maximum number of consecutive summer days (tmax >25 c) [day]`

`cf.ctmgeTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctmge`

: Maximum number of consecutive days with tmean >= c [day] `cf.ctmgtTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctmgt`

: Maximum number of consecutive days with tmean > c [day] `cf.ctmleTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctmle`

: Maximum number of consecutive days with tmean <= c [day] `cf.ctmltTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctmlt`

: Maximum number of consecutive days with tmean < c [day] `cf.ctngeTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctnge`

: Maximum number of consecutive days with tmin >= c [day] `cf.ctngtTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctngt`

: Maximum number of consecutive days with tmin > c [day] `cf.ctnleTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctnle`

: Maximum number of consecutive days with tmin <= c [day] `cf.ctnltTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctnlt`

: Maximum number of consecutive days with tmin < c [day] `cf.ctxgeTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctxge`

: Maximum number of consecutive days with tmax >= c [day] `cf.ctxgtTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctxgt`

: Maximum number of consecutive days with tmax > c [day] `cf.ctxleTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctxle`

: Maximum number of consecutive days with tmax <= c [day] `cf.ctxltTT`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`ctxlt`

: Maximum number of consecutive days with tmax < c [day] `cf.cwd`

:**Calculate statistics on lengths of spells.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Then the spells are determined, and finally the statistics according to the specified reducer are calculated.

**Based on**`xclim.indices.generic.spell_length`

**Produces:**`cwd: Maximum consecutive wet days (precip >= 1mm) [day]`

`cf.ddgtTT`

:**Calculate the temperature sum above/below a threshold.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Finally, the sum is calculated for those data values that fulfill the condition after subtraction of the threshold value. If the sum is for values below the threshold the result is multiplied by -1.

**Based on**`xclim.indices.generic.temperature_sum`

**Produces:**`ddgt`

: Degree days (tmean > c) [degree_Celsius day] `cf.ddltTT`

:**Calculate the temperature sum above/below a threshold.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Finally, the sum is calculated for those data values that fulfill the condition after subtraction of the threshold value. If the sum is for values below the threshold the result is multiplied by -1.

**Based on**`xclim.indices.generic.temperature_sum`

**Produces:**`ddlt`

: Degree days (tmean < c) [degree_Celsius day] `cf.dtr`

:**Calculate the diurnal temperature range and reduce according to a statistic.**-
**Description:**

**Based on**`xclim.indices.generic.diurnal_temperature_range`

**Produces:**`dtr: Mean diurnal temperature range [degree_Celsius]`

`cf.etr`

:**Calculate the extreme temperature range as the maximum of daily maximum temperature minus the minimum of daily minimum temperature.**-
**Description:**

**Based on**`xclim.indices.generic.extreme_temperature_range`

**Produces:**`etr: Intra-period extreme temperature range [degree_Celsius]`

`cf.fg`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`fg: Mean of daily mean wind strength [meter second-1]`

`cf.fxx`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`fxx: Maximum value of daily maximum wind gust strength [meter second-1]`

`cf.gd4`

:**Calculate the temperature sum above/below a threshold.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Finally, the sum is calculated for those data values that fulfill the condition after subtraction of the threshold value. If the sum is for values below the threshold the result is multiplied by -1.

**Based on**`xclim.indices.generic.temperature_sum`

**Produces:**`gd4: Growing degree days (sum of tmean > 4 c) [degree_Celsius day]`

`cf.gddgrowTT`

:**Calculate the temperature sum above/below a threshold.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Finally, the sum is calculated for those data values that fulfill the condition after subtraction of the threshold value. If the sum is for values below the threshold the result is multiplied by -1.

**Based on**`xclim.indices.generic.temperature_sum`

**Produces:**`gddgrow`

: Annual growing degree days (tmean > c) [degree_Celsius day] `cf.hd17`

:**Calculate the temperature sum above/below a threshold.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Finally, the sum is calculated for those data values that fulfill the condition after subtraction of the threshold value. If the sum is for values below the threshold the result is multiplied by -1.

**Based on**`xclim.indices.generic.temperature_sum`

**Produces:**`hd17: Heating degree days (sum of tmean < 17 c) [degree_Celsius day]`

`cf.hddheatTT`

:**Calculate the temperature sum above/below a threshold.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Finally, the sum is calculated for those data values that fulfill the condition after subtraction of the threshold value. If the sum is for values below the threshold the result is multiplied by -1.

**Based on**`xclim.indices.generic.temperature_sum`

**Produces:**`hddheat`

: Heating degree days (tmean < c) [degree_Celsius day] `cf.maxdtr`

:**Calculate the diurnal temperature range and reduce according to a statistic.**-
**Description:**

**Based on**`xclim.indices.generic.diurnal_temperature_range`

**Produces:**`maxdtr: Maximum diurnal temperature range [degree_Celsius]`

`cf.pp`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`pp: Mean of daily sea level pressure [hPa]`

`cf.rh`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`rh: Mean of daily relative humidity [%]`

`cf.sd`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`sd: Mean of daily snow depth [cm]`

`cf.sdii`

:**Calculate a simple statistic of the data for which some condition is met.**-
**Description:**First, the threshold is transformed to the same standard_name and units as the input data. Then the thresholding is performed as condition(data, threshold), i.e. if condition is <, data < threshold. Finally, the statistic is calculated for those data values that fulfill the condition.

**Based on**`xclim.indices.generic.thresholded_statistics`

**Produces:**`sdii: Average precipitation during wet days (sdii) [mm day-1]`

`cf.ss`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`ss: Sunshine duration, sum [hour]`

`cf.tg`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tg: Mean of daily mean temperature [degree_Celsius]`

`cf.tmm`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tmm: Mean daily mean temperature [degree_Celsius]`

`cf.tmmax`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tmmax: Maximum daily mean temperature [degree_Celsius]`

`cf.tmmean`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tmmean: Mean daily mean temperature [degree_Celsius]`

`cf.tmmin`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tmmin: Minimum daily mean temperature [degree_Celsius]`

`cf.tmn`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tmn: Minimum daily mean temperature [degree_Celsius]`

`cf.tmx`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tmx: Maximum daily mean temperature [degree_Celsius]`

`cf.tn`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tn: Mean of daily minimum temperature [degree_Celsius]`

`cf.tnm`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tnm: Mean daily minimum temperature [degree_Celsius]`

`cf.tnmax`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tnmax: Maximum daily minimum temperature [degree_Celsius]`

`cf.tnmean`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tnmean: Mean daily minimum temperature [degree_Celsius]`

`cf.tnmin`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tnmin: Minimum daily minimum temperature [degree_Celsius]`

`cf.tnn`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tnn: Minimum daily minimum temperature [degree_Celsius]`

`cf.tnx`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tnx: Maximum daily minimum temperature [degree_Celsius]`

`cf.tx`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`tx: Mean of daily maximum temperature [degree_Celsius]`

`cf.txm`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`txm: Mean daily maximum temperature [degree_Celsius]`

`cf.txmax`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`txmax: Maximum daily maximum temperature [degree_Celsius]`

`cf.txmean`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`txmean: Mean daily maximum temperature [degree_Celsius]`

`cf.txmin`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`txmin: Minimum daily maximum temperature [degree_Celsius]`

`cf.txn`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`txn: Minimum daily maximum temperature [degree_Celsius]`

`cf.txx`

:**Calculate a simple statistic of the data.**-
**Description:**

**Based on**`xclim.indices.generic.statistics`

**Produces:**`txx: Maximum daily maximum temperature [degree_Celsius]`

`cf.vdtr`

:**Calculate the average absolute day-to-day difference in diurnal temperature range.**-
**Description:**

**Based on**`xclim.indices.generic.interday_diurnal_temperature_range`

**Produces:**`vdtr: Mean day-to-day variation in diurnal temperature range [degree_Celsius]`

### ICCLIM indices

The European Climate Assessment & Dataset project (ECAD) defines a set of 26 core climate indices. Those have been made accessible directly in xclim through their ECAD name for compatibility. However, the methods in this module are only wrappers around the corresponding methods of xclim.indices. Note that none of the checks performed by the xclim.utils.Indicator class (like with xclim.atmos indicators)are performed in this module.

`icclim.BEDD`

:**Biologically effective growing degree days.**-
**Description:**Growing-degree days with a base of 10°C and an upper limit of 19°C and adjusted for latitudes between 40°N and 50°N for April to October (Northern Hemisphere; October to April in Southern Hemisphere). A temperature range adjustment also promotes small and large swings in daily temperature range. Used as a heat-summation metric in viticulture agroclimatology.

**Based on**`xclim.indices.biologically_effective_degree_days`

**Produces:**`BEDD: Biologically effective growing degree days (summation of min(max((tmin + tmax)/2 - 10°c, 0), 9°c), for days between 1 april and 30 september) [K days]`

`icclim.CD`

:**Cold and dry days**-
**Description:**Number of days with temperature below a given percentile and precipitation below a given percentile.

**Based on**`xclim.indices.cold_and_dry_days`

**Produces:**`CD: Cold and dry days [days]`

`icclim.CDD`

:**Maximum consecutive dry days**-
**Description:**The longest number of consecutive days where daily precipitation below a given threshold.

**Based on**`xclim.indices.maximum_consecutive_dry_days`

**Produces:**`CDD: Maximum number of consecutive dry days (rr<1 mm) [days]`

`icclim.CFD`

:**Consecutive frost days**-
**Description:**Maximum number of consecutive days where the daily minimum temperature is below 0°C

**Based on**`xclim.indices.maximum_consecutive_frost_days`

**Produces:**`CFD: Maximum number of consecutive frost days (tn<0°c) [days]`

`icclim.CSDI`

:**Cold Spell Duration Index (CSDI)**-
**Description:**Number of days part of a percentile-defined cold spell. A cold spell occurs when the daily minimum temperature is below a given percentile for a given number of consecutive days.

**Based on**`xclim.indices.cold_spell_duration_index`

**Produces:**`CSDI: Cold-spell duration index [days]`

`icclim.CSU`

:**Maximum consecutive warm days**-
**Description:**Maximum number of consecutive days where the maximum daily temperature exceeds a certain threshold.

**Based on**`xclim.indices.maximum_consecutive_tx_days`

**Produces:**`CSU: Maximum number of consecutive summer day [days]`

`icclim.CW`

:**Cold and wet days**-
**Description:**Number of days with temperature below a given percentile and precipitation above a given percentile.

**Based on**`xclim.indices.cold_and_wet_days`

**Produces:**`CW: Cold and wet days [days]`

`icclim.CWD`

:**Maximum consecutive wet days**-
**Description:**The longest number of consecutive days where daily precipitation is at or above a given threshold.

**Based on**`xclim.indices.maximum_consecutive_wet_days`

**Produces:**`CWD: Maximum number of consecutive wet days (rr≥1 mm) [days]`

`icclim.DTR`

:**Mean of daily temperature range**-
**Description:**The average difference between the daily maximum and minimum temperatures.

**Based on**`xclim.indices.daily_temperature_range`

**Produces:**`DTR: Mean of diurnal temperature range [K]`

`icclim.ETR`

:**Extreme temperature range**-
**Description:**The maximum of the maximum temperature minus the minimum of the minimum temperature.

**Based on**`xclim.indices.extreme_temperature_range`

**Produces:**`ETR: Intra-period extreme temperature range [K]`

`icclim.FD`

:**Frost days**-
**Description:**Number of days where the daily minimum temperature is below a given threshold.

**Based on**`xclim.indices.frost_days`

**Produces:**`FD: Frost days (tn<0°c) [days]`

`icclim.GD4`

:**Growing degree days**-
**Description:**The cumulative degree days for days when the average temperature is above a given threshold.

**Based on**`xclim.indices.growing_degree_days`

**Produces:**`GD4: Growing degree days (sum of tg>4°c) [K days]`

`icclim.GSL`

:**Growing season length**-
**Description:**Number of days between the first occurrence of a series of days with a daily average temperature above a threshold and the first occurrence of a series of days with a daily average temperature below that same threshold, occurring after a given calendar date.

**Based on**`xclim.indices.growing_season_length`

**Produces:**`GSL: Growing season length [days]`

`icclim.HD17`

:**Heating degree days**-
**Description:**The cumulative degree days for days when the mean daily temperature is below a given threshold and buildings must be heated.

**Based on**`xclim.indices.heating_degree_days`

**Produces:**`HD17: Heating degree days (sum of17°c - tg) [K days]`

`icclim.HI`

:**Huglin Heliothermal Index.**-
**Description:**Growing-degree days with a base of 10°C and adjusted for latitudes between 40°N and 50°N for April-September (Northern Hemisphere; October-March in Southern Hemisphere). Originally proposed in :cite:t:`huglin_nouveau_1978`. Used as a heat-summation metric in viticulture agroclimatology.

**Based on**`xclim.indices.huglin_index`

**Produces:**`HI: Huglin heliothermal index (summation of ((tmean + tmax)/2 - 10°c) * latitude-based day-length coefficient (`k`), for days between 1 april and 31 october) []`

`icclim.ID`

:**Ice days**-
**Description:**Number of days where the daily maximum temperature is below 0°C

**Based on**`xclim.indices.ice_days`

**Produces:**`ID: Ice days (tx<0°c) [days]`

`icclim.PRCPTOT`

:**Total accumulated precipitation (solid and liquid) during wet days**-
**Description:**Total accumulated precipitation on days with precipitation. A day is considered to have precipitation if the precipitation is greater than or equal to a given threshold.

**Based on**`xclim.indices.prcptot`

**Produces:**`PRCPTOT: Precipitation sum over wet days [mm]`

`icclim.R10mm`

:**Number of wet days**-
**Description:**The number of days with daily precipitation at or above a given threshold.

**Based on**`xclim.indices.wetdays`

**Produces:**`R10mm: Heavy precipitation days (precipitation≥10 mm) [days]`

`icclim.R20mm`

:**Number of wet days**-
**Description:**The number of days with daily precipitation at or above a given threshold.

**Based on**`xclim.indices.wetdays`

**Produces:**`R20mm: Very heavy precipitation days (precipitation≥20 mm) [days]`

`icclim.R75p`

:**Number of days with precipitation above a given percentile**-
**Description:**Number of days in a period where precipitation is above a given percentile, calculated over a given period and a fixed threshold.

**Based on**`xclim.indices.days_over_precip_thresh`

**Produces:**`R75p: Number of days with precipitation flux above the {unknown}th percentile of {unknown} [days]`

`icclim.R75pTOT`

:**Fraction of precipitation due to wet days with daily precipitation over a given percentile.**-
**Description:**Percentage of the total precipitation over period occurring in days when the precipitation is above a threshold defining wet days and above a given percentile for that day.

**Based on**`xclim.indices.fraction_over_precip_thresh`

**Produces:**`R75pTOT: Precipitation fraction due to moderate wet days (>75th percentile) []`

`icclim.R95p`

:**Number of days with precipitation above a given percentile**-
**Description:**Number of days in a period where precipitation is above a given percentile, calculated over a given period and a fixed threshold.

**Based on**`xclim.indices.days_over_precip_thresh`

**Produces:**`R95p: Number of days with precipitation flux above the {unknown}th percentile of {unknown} [days]`

`icclim.R95pTOT`

:**Fraction of precipitation due to wet days with daily precipitation over a given percentile.**-
**Description:**Percentage of the total precipitation over period occurring in days when the precipitation is above a threshold defining wet days and above a given percentile for that day.

**Based on**`xclim.indices.fraction_over_precip_thresh`

**Produces:**`R95pTOT: Precipitation fraction due to very wet days (>95th percentile) []`

`icclim.R99p`

:**Number of days with precipitation above a given percentile**-
**Description:**Number of days in a period where precipitation is above a given percentile, calculated over a given period and a fixed threshold.

**Based on**`xclim.indices.days_over_precip_thresh`

**Produces:**`R99p: Number of days with precipitation flux above the {unknown}th percentile of {unknown} [days]`

`icclim.R99pTOT`

:**Fraction of precipitation due to wet days with daily precipitation over a given percentile.**-
**Description:**Percentage of the total precipitation over period occurring in days when the precipitation is above a threshold defining wet days and above a given percentile for that day.

**Based on**`xclim.indices.fraction_over_precip_thresh`

**Produces:**`R99pTOT: Precipitation fraction due to extremely wet days (>99th percentile) []`

`icclim.RR`

:**Total accumulated precipitation (solid and liquid)**-
**Description:**Total accumulated precipitation. If the average daily temperature is given, the phase parameter can be used to restrict the calculation to precipitation of only one phase (liquid or solid). Precipitation is considered solid if the average daily temperature is below 0°C (and vice versa).

**Based on**`xclim.indices.precip_accumulation`

**Produces:**`RR: Precipitation sum [mm]`

`icclim.RR1`

:**Number of wet days**-
**Description:**The number of days with daily precipitation at or above a given threshold.

**Based on**`xclim.indices.wetdays`

**Produces:**`RR1: Wet days (rr≥1 mm) [days]`

`icclim.RX1day`

:**Maximum 1-day total precipitation**-
**Description:**Maximum total daily precipitation for a given period.

**Based on**`xclim.indices.max_1day_precipitation_amount`

**Produces:**`RX1day: Highest 1-day precipitation amount [mm/day]`

`icclim.RX5day`

:**maximum n-day total precipitation**-
**Description:**Maximum of the moving sum of daily precipitation for a given period.

**Based on**`xclim.indices.max_n_day_precipitation_amount`

**Produces:**`RX5day: Highest 5-day precipitation amount [mm]`

`icclim.SD`

:**Mean snow depth**-
**Description:**Mean of daily snow depth.

**Based on**`xclim.indices.snow_depth`

**Produces:**`SD: Mean of daily snow depth [cm]`

`icclim.SD1`

:**Snow cover duration**-
**Description:**Number of days when the snow depth is greater than or equal to a given threshold.

**Based on**`xclim.indices.snow_cover_duration`

**Produces:**`SD1: Snow days (sd≥1 cm) [days]`

`icclim.SD50cm`

:**Snow cover duration**-
**Description:**Number of days when the snow depth is greater than or equal to a given threshold.

**Based on**`xclim.indices.snow_cover_duration`

**Produces:**`SD50cm: Snow days (sd≥50 cm) [days]`

`icclim.SD5cm`

:**Snow cover duration**-
**Description:**Number of days when the snow depth is greater than or equal to a given threshold.

**Based on**`xclim.indices.snow_cover_duration`

**Produces:**`SD5cm: Snow days (sd≥5 cm) [days]`

`icclim.SDII`

:**Simple Daily Intensity Index**-
**Description:**Average precipitation for days with daily precipitation above a given threshold.

**Based on**`xclim.indices.daily_pr_intensity`

**Produces:**`SDII: Average precipitation during days with daily precipitation over 1 mm/day (simple daily intensity index: sdii) [mm d-1]`

`icclim.SU`

:**Number of days with maximum temperature above a given threshold**-
**Description:**The number of days with maximum temperature above a given threshold.

**Based on**`xclim.indices.tx_days_above`

**Produces:**`SU: Summer days (tx>25°c) [days]`

`icclim.TG`

:**Mean temperature**-
**Description:**Mean of daily mean temperature.

**Based on**`xclim.indices.tg_mean`

**Produces:**`TG: Mean daily mean temperature [K]`

`icclim.TG10p`

:**Days with mean temperature below the 10th percentile**-
**Description:**Number of days with mean temperature below the 10th percentile.

**Based on**`xclim.indices.tg10p`

**Produces:**`TG10p: Days with tg<10th percentile of daily mean temperature (cold days) [days]`

`icclim.TG90p`

:**Days with mean temperature above the 90th percentile**-
**Description:**Number of days with mean temperature above the 90th percentile.

**Based on**`xclim.indices.tg90p`

**Produces:**`TG90p: Days with tg>90th percentile of daily mean temperature (warm days) [days]`

`icclim.TGn`

:**Minimum of mean temperature**-
**Description:**Minimum of daily mean temperature.

**Based on**`xclim.indices.tg_min`

**Produces:**`TGn: Minimum daily mean temperature [K]`

`icclim.TGx`

:**Maximum of mean temperature**-
**Description:**Maximum of daily mean temperature.

**Based on**`xclim.indices.tg_max`

**Produces:**`TGx: Maximum daily mean temperature [K]`

`icclim.TN`

:**Mean of minimum temperature**-
**Description:**Mean of daily minimum temperature.

**Based on**`xclim.indices.tn_mean`

**Produces:**`TN: Mean daily minimum temperature [K]`

`icclim.TN10p`

:**Days with minimum temperature below the 10th percentile**-
**Description:**Number of days with minimum temperature below the 10th percentile.

**Based on**`xclim.indices.tn10p`

**Produces:**`TN10p: Days with tn<10th percentile of daily minimum temperature (cold nights) [days]`

`icclim.TN90p`

:**Days with minimum temperature above the 90th percentile**-
**Description:**Number of days with minimum temperature above the 90th percentile.

**Based on**`xclim.indices.tn90p`

**Produces:**`TN90p: Days with tn>90th percentile of daily minimum temperature (warm nights) [days]`

`icclim.TNn`

:**Minimum temperature**-
**Description:**Minimum of daily minimum temperature.

**Based on**`xclim.indices.tn_min`

**Produces:**`TNn: Minimum daily minimum temperature [K]`

`icclim.TNx`

:**Maximum of minimum temperature**-
**Description:**Maximum of daily minimum temperature.

**Based on**`xclim.indices.tn_max`

**Produces:**`TNx: Maximum daily minimum temperature [K]`

`icclim.TR`

:**Tropical nights**-
**Description:**Number of days where minimum temperature is above a given threshold.

**Based on**`xclim.indices.tn_days_above`

**Produces:**`TR: Tropical nights (tn>20°c) [days]`

`icclim.TX`

:**Mean of maximum temperature**-
**Description:**Mean of daily maximum temperature.

**Based on**`xclim.indices.tx_mean`

**Produces:**`TX: Mean daily maximum temperature [K]`

`icclim.TX10p`

:**Days with maximum temperature below the 10th percentile**-
**Description:**Number of days with maximum temperature below the 10th percentile.

**Based on**`xclim.indices.tx10p`

**Produces:**`TX10p: Days with tx<10th percentile of daily maximum temperature (cold day-times) [days]`

`icclim.TX90p`

:**Days with maximum temperature above the 90th percentile**-
**Description:**Number of days with maximum temperature above the 90th percentile.

**Based on**`xclim.indices.tx90p`

**Produces:**`TX90p: Days with tx>90th percentile of daily maximum temperature (warm day-times) [days]`

`icclim.TXn`

:**Minimum of maximum temperature**-
**Description:**Minimum of daily maximum temperature.

**Based on**`xclim.indices.tx_min`

**Produces:**`TXn: Minimum daily maximum temperature [K]`

`icclim.TXx`

:**Maximum temperature**-
**Description:**Maximum of daily maximum temperature.

**Based on**`xclim.indices.tx_max`

**Produces:**`TXx: Maximum daily maximum temperature [K]`

`icclim.WD`

:**Warm and dry days**-
**Description:**Number of days with temperature above a given percentile and precipitation below a given percentile.

**Based on**`xclim.indices.warm_and_dry_days`

**Produces:**`WD: Warm and dry days [days]`

`icclim.WSDI`

:**Warm spell duration index**-
**Description:**Number of days part of a percentile-defined warm spell. A warm spell occurs when the maximum daily temperature is above a given percentile for a given number of consecutive days.

**Based on**`xclim.indices.warm_spell_duration_index`

**Produces:**`WSDI: Warm-spell duration index [days]`

`icclim.WW`

:**Warm and wet days**-
**Description:**Number of days with temperature above a given percentile and precipitation above a given percentile.

**Based on**`xclim.indices.warm_and_wet_days`

**Produces:**`WW: Warm and wet days [days]`

`icclim.vDTR`

:**Variability of daily temperature range**-
**Description:**The average day-to-day variation in daily temperature range.

**Based on**`xclim.indices.daily_temperature_range_variability`

**Produces:**`vDTR: Mean absolute day-to-day difference in dtr [K]`

### ANUCLIM indices

The ANUCLIM (v6.1) software package BIOCLIM sub-module produces a set of bioclimatic parameters derived values of
temperature and precipitation. The methods in this module are wrappers around a subset of corresponding methods of
`xclim.indices`

.

Furthermore, according to the ANUCLIM user-guide [Xu and Hutchinson, 2010], input values should be at a weekly or monthly frequency. However, the implementation here expands these definitions and can calculate the result with daily input data.

`anuclim.P10_MeanTempWarmestQuarter`

:**Mean temperature of warmest/coldest quarter.**-
**Description:**The warmest (or coldest) quarter of the year is determined, and the mean temperature of this period is calculated. If the input data frequency is daily ("D") or weekly ("W"), quarters are defined as 13-week periods, otherwise as three (3) months.

**Based on**`xclim.indices.tg_mean_warmcold_quarter`

**Produces:**`P10_MeanTempWarmestQuarter: [K]`

`anuclim.P11_MeanTempColdestQuarter`

:**Mean temperature of warmest/coldest quarter.**-
**Description:**The warmest (or coldest) quarter of the year is determined, and the mean temperature of this period is calculated. If the input data frequency is daily ("D") or weekly ("W"), quarters are defined as 13-week periods, otherwise as three (3) months.

**Based on**`xclim.indices.tg_mean_warmcold_quarter`

**Produces:**`P11_MeanTempColdestQuarter: [K]`

`anuclim.P12_AnnualPrecip`

:**Accumulated total precipitation.**-
**Description:**The total accumulated precipitation from days where precipitation exceeds a given amount. A threshold is provided in order to allow the option of reducing the impact of days with trace precipitation amounts on period totals.

**Based on**`xclim.indices.prcptot`

**Produces:**`P12_AnnualPrecip: Annual precipitation [mm]`

`anuclim.P13_PrecipWettestPeriod`

:**Precipitation of the wettest/driest day, week, or month, depending on the time step.**-
**Description:**The wettest (or driest) period is determined, and the total precipitation of this period is calculated.

**Based on**`xclim.indices.prcptot_wetdry_period`

**Produces:**`P13_PrecipWettestPeriod: [mm]`

`anuclim.P14_PrecipDriestPeriod`

:**Precipitation of the wettest/driest day, week, or month, depending on the time step.**-
**Description:**The wettest (or driest) period is determined, and the total precipitation of this period is calculated.

**Based on**`xclim.indices.prcptot_wetdry_period`

**Produces:**`P14_PrecipDriestPeriod: [mm]`

`anuclim.P15_PrecipSeasonality`

:**Precipitation Seasonality (C of V).**-
**Description:**The annual precipitation Coefficient of Variation (C of V) expressed in percent. Calculated as the standard deviation of precipitation values for a given year expressed as a percentage of the mean of those values.

**Based on**`xclim.indices.precip_seasonality`

**Produces:**`P15_PrecipSeasonality: []`

`anuclim.P16_PrecipWettestQuarter`

:**Total precipitation of wettest/driest quarter.**-
**Description:**The wettest (or driest) quarter of the year is determined, and the total precipitation of this period is calculated. If the input data frequency is daily ("D") or weekly ("W") quarters are defined as 13-week periods, otherwise are three (3) months.

**Based on**`xclim.indices.prcptot_wetdry_quarter`

**Produces:**`P16_PrecipWettestQuarter: [mm]`

`anuclim.P17_PrecipDriestQuarter`

:**Total precipitation of wettest/driest quarter.**-
**Description:**The wettest (or driest) quarter of the year is determined, and the total precipitation of this period is calculated. If the input data frequency is daily ("D") or weekly ("W") quarters are defined as 13-week periods, otherwise are three (3) months.

**Based on**`xclim.indices.prcptot_wetdry_quarter`

**Produces:**`P17_PrecipDriestQuarter: [mm]`

`anuclim.P18_PrecipWarmestQuarter`

:**Total precipitation of warmest/coldest quarter.**-
**Description:**The warmest (or coldest) quarter of the year is determined, and the total precipitation of this period is calculated. If the input data frequency is daily ("D) or weekly ("W"), quarters are defined as 13-week periods, otherwise are 3 months.

**Based on**`xclim.indices.prcptot_warmcold_quarter`

**Produces:**`P18_PrecipWarmestQuarter: [mm]`

`anuclim.P19_PrecipColdestQuarter`

:**Total precipitation of warmest/coldest quarter.**-
**Description:**The warmest (or coldest) quarter of the year is determined, and the total precipitation of this period is calculated. If the input data frequency is daily ("D) or weekly ("W"), quarters are defined as 13-week periods, otherwise are 3 months.

**Based on**`xclim.indices.prcptot_warmcold_quarter`

**Produces:**`P19_PrecipColdestQuarter: [mm]`

`anuclim.P1_AnnMeanTemp`

:**Mean of daily average temperature.**-
**Description:**Resample the original daily mean temperature series by taking the mean over each period.

**Based on**`xclim.indices.tg_mean`

**Produces:**`P1_AnnMeanTemp: Annual mean temperature [K]`

`anuclim.P2_MeanDiurnalRange`

:**Statistics of daily temperature range.**-
**Description:**The mean difference between the daily maximum temperature and the daily minimum temperature.

**Based on**`xclim.indices.daily_temperature_range`

**Produces:**`P2_MeanDiurnalRange: Mean diurnal range [K]`

`anuclim.P3_Isothermality`

:**Isothermality.**-
**Description:**The mean diurnal temperature range divided by the annual temperature range.

**Based on**`xclim.indices.isothermality`

**Produces:**`P3_Isothermality: []`

`anuclim.P4_TempSeasonality`

:**Temperature seasonality (coefficient of variation).**-
**Description:**The annual temperature coefficient of variation expressed in percent. Calculated as the standard deviation of temperature values for a given year expressed as a percentage of the mean of those temperatures.

**Based on**`xclim.indices.temperature_seasonality`

**Produces:**`P4_TempSeasonality: []`

`anuclim.P5_MaxTempWarmestPeriod`

:**Highest max temperature.**-
**Description:**The maximum value of daily maximum temperature.

**Based on**`xclim.indices.tx_max`

**Produces:**`P5_MaxTempWarmestPeriod: Max temperature of warmest period [K]`

`anuclim.P6_MinTempColdestPeriod`

:**Lowest minimum temperature.**-
**Description:**Minimum of daily minimum temperature.

**Based on**`xclim.indices.tn_min`

**Produces:**`P6_MinTempColdestPeriod: Min temperature of coldest period [K]`

`anuclim.P7_TempAnnualRange`

:**Calculate the extreme temperature range as the maximum of daily maximum temperature minus the minimum of daily minimum temperature.**-
**Description:**

**Based on**`xclim.indices.generic.extreme_temperature_range`

**Produces:**`P7_TempAnnualRange: Temperature annual range [K]`

`anuclim.P8_MeanTempWettestQuarter`

:**Mean temperature of wettest/driest quarter.**-
**Description:**The wettest (or driest) quarter of the year is determined, and the mean temperature of this period is calculated. If the input data frequency is daily ("D") or weekly ("W"), quarters are defined as 13-week periods, otherwise are 3 months.

**Based on**`xclim.indices.tg_mean_wetdry_quarter`

**Produces:**`P8_MeanTempWettestQuarter: [K]`

`anuclim.P9_MeanTempDriestQuarter`

:**Mean temperature of wettest/driest quarter.**-
**Description:**The wettest (or driest) quarter of the year is determined, and the mean temperature of this period is calculated. If the input data frequency is daily ("D") or weekly ("W"), quarters are defined as 13-week periods, otherwise are 3 months.

**Based on**`xclim.indices.tg_mean_wetdry_quarter`

**Produces:**`P9_MeanTempDriestQuarter: [K]`