Fire weather information is important because it describes the prevailing weather conditions affecting fire behaviour. The most important weather variables are wind, atmospheric humidity and temperature.

• Wind is a major controlling factor that determines rate and direction of spread, and shape of fire.
• Humidity is important because it affects fuel moisture content and therefore its flammability. For example, in dry conditions, moisture from fuels is transferred to the atmosphere and the fuels become increasingly flammable.
• Temperature affects fire behaviour indirectly through influence on fuel moisture content and local wind formation (e.g. sea-breezes). So, as air temperature increases, fuel moisture content tends to decrease, and vice versa. Dew can form which can cause fire to slow or even be extinguished. Also, the higher the temperature of the fuel, the more easily it will reach ignition temperature.

Fire weather information can be used in conjunction with fuel information to provide indices of fire hazard or danger rating. Fire Danger Index (FDI) is estimated using the McArthur Fire Danger Meter for grasslands or forest. The higher the FDI, the higher the fire danger. The Mark IV Grassland Meter (or CSIRO Grassland Fire Danger Meter) is most applicable in the grasslands and savanna.

Research found in this area of this site examines weather conditions which influence fire ignition, behavior, and suppression. The research also examines weather predictions specially prepared for use in wildland (bushfire) fire operations and prescribed fire.