National Weather Service United States Department of Commerce

Wildfire Infographics

 

The Speed of Wildfires:
Weather Conditions
Wind speed has a huge effect on fire intensity and how fast fires travel. Wind pushes the flame forward and closer to the unburned fuel in front of the fire. Temperature, humidity, and precipitation are also important due to their strong influence on fuel moisture content.

Spotting
Wind and thermals can carry sparks and firebrands downwind of fires, greatly increasing spread rates.

Fuel Type
The type of vegetation along with the fuel moisture content, physical properties, and chemical properties play a role in fire behavior and how fast fires spread.

Topography
Slope steepness affects fire behavior in a similar way as wind by changing the flame angle. Elevation and aspect are also important in determining how fires spread.
Wildfire Safety:
Properly discard cigarettes. Keep vehicles off of dry grass. Avoid activities with open flames or sparks. Avoid power equipment that creates sparks. Obey burn bans. Evacuate if fire/smoke is heading your way. Evacuate if ordered to do so by local officials. weather.gov/wildfire
Red Flag Warning: The NWS issues a Red Flag Warning, in conjunction with land management agencies, to alert land managers to an ongoing or imminent critical fire weather pattern. Critical fire conditions are either occurring now, or will shortly.  Be extremely careful with open flames.
Fire Weather Watch: A Fire Weather alerts land managers that upcoming weather conditions could result in extensive wildland fire occurence or extreme fire behavior. A watch means critical fire weather conditions are possible but not imminent or occurring.
Red Flag Warning: Be extremely careful with open flames. The NWS issues a Red Flag Warning, in conjunction with land management agencies, to alert land managers to an ongoing or imminent critical fire weather pattern. Critical fire conditions are either occurring now, or will shortly.  Be extremely careful with open flames.