Anatomy of a Wildfire

Fire: A Product of the Environment
Fuel, heat, and oxygen form what is known as the “fire triangle.” With these elements in place, all that is required for a fire to start is an ignition source, such as lightning or a match. A fire’s intensity is determined by a variety of factors including the amount of available fuel (trees, grasses, leaves, and other debris), weather conditions, and the layout of the land. Fires spread easily when the weather is…

• Hot: Fire intensity is generally directly proportional to the temperature.
• Dry: The less humid the air, the more easily fire burns.
• Windy: Wind brings in extra oxygen and helps fire spread.

In California, the warm Santa Ana winds, which occur in the fall and winter, combined with low humidity and dry land conditions, create ideal wildfire conditions.

The Current Situation
Over 100,000 wildfires fires occur every year in the United States. Wildfire
activity is seasonal: In the West, most fires occur between June and October,
in the Southeast the fire season is generally March through June, and most
fires occur in New England in the autumn.

• California: As of October 24, 2007, 15 wildfires in California were burning more than 414,000 acres of land.
• Year-to-Date: Since January 1, 2007, there have been 76,575 wildfires in the U.S., which have burned 8,346,757 acres of land.

Protect Your Home and Property from Wildfire
• Find out when wildfire is most likely to occur in your area by visiting the US Forest Service “Normal Peak Wildfire Seasons” tool: www.firewise.org/resources/peak_fire_seasons/index.html.
• Thirty feet around your house should be a “lean, green, and clean” defensible space:
o Lean: Prune trees and shrubs, and make sure that overhanging tree branches are no less than 15 feet from any structure. The lowest branches on trees should be six- to ten-feet from the ground.
o Green: Plant healthy, fire-resistant plants. Your local garden center of County Extension Office can help you find plants that are right for your property and climate.
o Clean: Remove easily flammable vegetation, including leaves, dead wood and firewood, and dry grass.
• Keep your lawn mowed, especially if the grass is dry.
• Remove dead leaves and other debris from your gutters.
• Use fire-resistant building materials whenever possible. Consider using slate, metal, or clay roofing materials; wood roofing is particularly vulnerable to fire.
• Double paned windows made with tempered glass hold up against fire much better than single paned windows; plastic skylights can melt under high temperatures.
• Hosing down your yard and especially your roof when a wildfire is close by can help to keep the flames from consuming your property. Make sure your hose is in good working order.
• Pay attention to local weather warnings and have a home evacuation plan in place. Always follow the evacuation and safety directions issued by local authorities.
• For more information on protecting your home visit Firewise Communities: www.firewise.org.