Fire Weather Index Calculator

Estimate fire weather risk from temperature, relative humidity, wind speed, recent rainfall, drought level, fuel dryness, slope, and lightning risk. This calculator gives a rough fire weather score for planning and awareness.

Calculate Fire Weather Risk

Fire Weather Score = heat + low humidity + wind + fuel dryness + drought + slope + lightning − rainfall reduction
Your result will appear here.

How the fire weather index calculator works

Temperature and humidity:
Hot, dry air increases fire weather risk because fuels can dry faster and ignite more easily.

Wind speed:
Wind can help fires spread faster, push flames into new fuels, and carry embers ahead of the fire.

Rainfall and drought:
Recent rainfall lowers the score, while drought and dry fuels increase it.

Slope and lightning:
Slopes can increase fire spread potential, and lightning can add ignition risk.

Why use a fire weather index calculator?

A fire weather index calculator is useful for rough wildfire awareness, outdoor burning checks, yard work planning, camping, land management, farming, forestry, and understanding how weather affects fire danger.

This is a rough educational estimate, not an official fire danger rating. Always follow local fire restrictions, red flag warnings, burn bans, and emergency management guidance.

What your result means

Your result shows an estimated fire weather score from 0 to 100. Higher scores mean weather and fuel conditions are more favorable for ignition, fast spread, or difficult control. Lower scores mean the entered conditions are less supportive of fire spread.

Fire weather safety tips

Frequently asked questions

What is fire weather?

Fire weather refers to weather conditions that increase the chance of fire ignition, spread, or difficulty controlling a fire.

What weather conditions increase wildfire risk?

Hot temperatures, low humidity, strong wind, dry fuels, drought, steep terrain, and lightning can all increase fire weather risk.

Does rain always remove fire danger?

No. Rain can reduce fire risk, but dry air, wind, heat, and drought can dry fine fuels again quickly.

Is this an official fire danger rating?

No. This calculator is a rough planning estimate only. Use official fire weather warnings, burn bans, and local fire danger ratings for real decisions.