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Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.


r.bioclim - Calcuates bioclimatic indices.


raster, time series


r.bioclim --help
r.bioclim tmin=name[,name,...] tmax=name[,name,...] [tavg=name[,name,...]] [precipitation=name[,name,...]] output=string [tinscale=integer] [toutscale=integer] [quartals=integer] [workers=integer] [--overwrite] [--help] [--verbose] [--quiet] [--ui]


Allow output files to overwrite existing files
Print usage summary
Verbose module output
Quiet module output
Force launching GUI dialog


tmin=name[,name,...] [required]
Monthly minimum temperatures
Monthly minimum temperatures for 12 months
tmax=name[,name,...] [required]
Monthly maximum temperatures
Monthly maximum temperatures for 12 months
Monthly average temperatures
Monthly average temperatures for 12 months
Monthly precipitation
Monthly average precipitation for 12 months
output=string [required]
Prefix for output maps
Scale factor for input temperature
Default: 1
Scale factor for output temperature
Default: 10
Number of quartals to use
Options: 4, 12
Default: 4
Number of parallel processes to launch
Options: 1-12
Default: 1

Table of contents


r.bioclim calculates various bioclimatic indices from monthly temperature and optional precipitation time series. The time series can be averages for several years or monthly values for a specific year. In any case all 12 months must be provided. If a precipitation time series is not provided, only those indices based on temperature are calculated. The names of the output maps are <output>bio01, <output>bio02, <output>bio03, etc. If the suffix bioXY needs to be separated from the output prefix, that separator must be part of the prefix, e.g. output=eurolst_.

If the input temperatures are scaled, e.g. as input = Celsius * 10, then the inscale option must be set to 10. Similarly, the outscale option is by default 10, and temperature output is in this case Celsius * 10. Exceptions are BIO3, BIO4, and BIO15 which are always multiplied with 100 (see below). The reason that outscale is set to 10 by default is that the output layers are integers (for compatibility with WORLDCLIM), and a scaling factor of 10 (or higher power of 10) ensures a minimum of precision.


Quarter years

The bioclimatic indices referring to the wettest, driest, warmest or coldest quarter can be computed in two different ways. The default is to divide a year into four quarters (quarters=4). Using this option the first quarter refers to Jan - Mar, the second quarter to Apr - Jun, and the last quarter to Oct - Dec. It is the method used to create the 250m EuroLST bioclim data and should be used with records for a specific year.

The second option is to divide the year in 12 quarters. With this option the quarterly parameters are not aligned to any calendar quarters. Instead, the first quarter refers to Jan - Mar, the second quarter to Feb - Apr, and the last quarter to Dec - Feb. This is the same method as used by the biovars function in the R package dismo and how the bioclimatic variables provided by Worldclim were computed. This option should be used when long-term averages are used as input.

List of bioclimatic indices

BIO 01 Annual mean temperature as the mean of the monthly temperatures (°C)

BIO 02 Mean diurnal range as the mean of monthly (max temp - min temp) (°C)

BIO 03 Isothermality (BIO2/BIO7 * 100)

BIO 04 Temperature Seasonality (standard deviation * 100)

BIO 05 Max Temperature of Warmest Month (°C)

BIO 06 Min Temperature of Coldest Month (°C)

BIO 07 Temperature Annual Range (BIO5 - BIO6) (°C)

BIO 08 Mean Temperature of Wettest Quarter (°C)

BIO 09 Mean Temperature of Driest Quarter (°C)

BIO 10 Mean Temperature of Warmest Quarter (°C)

BIO 11 Mean Temperature of Coldest Quarter (°C)

BIO 12 Annual Precipitation (mm)

BIO 13 Precipitation of Wettest Month (mm)

BIO 14 Precipitation of Driest Month (mm)

BIO 15 Precipitation Seasonality (Coefficient of Variation * 100)

BIO 16 Precipitation of Wettest Quarter (mm)

BIO 17 Precipitation of Driest Quarter (mm)

BIO 18 Precipitation of Warmest Quarter (mm)

BIO 19 Precipitation of Coldest Quarter (mm)


Bioclimatic indices from worldclim data with 4 parallel processes:
r.bioclim tmin=`g.list type=rast pat=tmin_* map=. sep=,` \
          tmax=`g.list type=rast pat=tmax_* map=. sep=,` \
          prec=`g.list type=rast pat=prec_* map=. sep=,` \
          out=worldclim_ workers=4


r.series, r.mapcalc, g.region



Markus Metz


Available at: r.bioclim source code (history)

Latest change: Monday Jun 28 07:54:09 2021 in commit: 1cfc0af029a35a5d6c7dae5ca7204d0eb85dbc55

Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.

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