Fire Weather

Indices describing the likelihood that a fire could start or spread, based on recent weather conditions

  • Source: NASA

The Fire Weather data set is derived from the Fire Weather Index (FWI) System, which was developed by the Canadian Forest Service and is the most widely used fire danger rating system in the world. The Global Fire WEather Database (GFWED) is a global database of daily FWI System calculations, produced by National Aeronautics and Space Administration (NASA) Goddard Institute for Space Studies. This system combines different weather factors that may influence the start and spread of a vegetation fire and is comprised of three moisture codes and three fire behavior indices. The moisture codes describe the moisture content of three general fuel classes. The fire behavior indices describe the rate of spread, fuel consumption and intensity of a fire if it were to start.

The data inputs for these calculations are measurements of 12:00 local time temperature at 2 m, relative humidity at 2 m and wind speed at 10 m. Daily snow-depth and precipitation were totaled over the previous 24 hours. GFWED includes several different versions of these calculations, each of which uses a different input weather and precipitation data. The version of these calculations shown on Resource Watch uses input data from GEOS-5 for temperature, relative humidity, wind-speed and snow depth; input precipitation comes from the 'Late' version of GPM IMERG Daily Precipitation. Global daily calculations of the FWI System indices using these data inputs are available from 2015 to present with 0.1° resolution. Resource Watch shows only a subset of the data set. For access to the full data set and additional information, see the Learn More link.

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Formal name

Global Fire WEather Database (GFWED) Fire Weather Index (FWI) System


This data set uses the 'Late' version of the GPM IMERG Precipitation data set. This version has less assimilation and correction than the final version of this data set. Experimental, near real-time GEOS-5 data were used for temperature, relative humidity, wind speed, and daily snow-depth data.

Suggested citation

NASA Goddard Institute for Space Studies. “Global Fire Weather Database (GFWED).” Retrieved from Accessed through Resource Watch, (date).


National Aeronautics and Space Administration (NASA)

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