Weather tools

Fire Weather Index (FWI) Calculator

Calculates the Fire Weather Index (FWI), a numerical rating of fire danger based on factors like temperature, humidity, wind speed, and recent rainfall.

Before you use this tool

Use this if

  • Calculates the Fire Weather Index (FWI), a numerical rating of fire danger based on factors like temperature, humidity, wind speed, and recent rainfall.
  • You want a calculation that exposes its formula: FWI calculation involves complex formulas based on FFMC, DMC, DC, and wind speed. Refer to official FWI documentation for detailed equations.
  • You already have Temperature, Relative Humidity, Wind Speed values to enter.

Skip this if

  • You need an official emergency alert or life-safety instruction.
  • You need a certified professional forecast instead of a calculator estimate.
When to use or skip it

Use this if

  • Calculates the Fire Weather Index (FWI), a numerical rating of fire danger based on factors like temperature, humidity, wind speed, and recent rainfall.
  • You want a calculation that exposes its formula: FWI calculation involves complex formulas based on FFMC, DMC, DC, and wind speed. Refer to official FWI documentation for detailed equations.
  • You already have Temperature, Relative Humidity, Wind Speed values to enter.

Skip this if

  • You need an official emergency alert or life-safety instruction.
  • You need a certified professional forecast instead of a calculator estimate.