Wildfire Season

With a rapidly growing U.S. population in areas that are prone to wildfires, it is becoming increasingly important to understand the wildfire season. Since the year 2000, there has been an average of 76,874 individual fires across the U.S. per year which have burned approximately 7,844,363 acres a year. The cost to fight these fires equates to an average annual cost of $1,318,571,250.

The most prone areas for wildfires are across the western half of the United States, particularly the Desert Southwest, as well as interior California and the interior Pacific Northwest. The wildfire season starts ramping up in June and lasts through October. The wildfire season can vary by a month or so in length from year to year due to several meteorological factors. Two of these factors include how wet the year's winter season was, and how wet the upcoming summer and fall seasons will be. Soil moisture will dry quicker in the spring and the mountain snow pack will melt quicker if the prior winter season is drier than average. In addition, a drier-than-normal weather pattern in the summer and fall months do not help with fighting fires that have naturally erupted. Even wetter-than-normal winter seasons can have a negative impact on the wildfire season. More precipitation in the winter will lead to more vegetation and shrub growth which eventually will dry out in the spring or early summer. These dried out shrubs and vegetation then can become fuel for wildfires during the summer and into the fall. The only significantly beneficial weather pattern for a limited wildfire season is a wetter-than-normal summer and fall across the greatest wildfire prone areas.

A majority of wildfires are caused by lightning strikes from low precipitation thunderstorms that pop up during the day and evening hours. They frequently get started when lightning strikes dried out shrubs or vegetation. Just last year in 2012, lightning induced wildfires caused 6,825,989 acres to be burned, which accounts for about 63% of all acres burned that year.

More Weather Glossary

Daily U.S. Extremes

past 24 hours

  Extreme Location
High N/A
Low N/A
Precip N/A

WeatherWhys®

This Day In Weather History

Amarillo, TX (1982)
4.22" of rain -- 24-hour July rainfall record.

Eureka, CA (1982)
A total of 0.03" in drizzle -- a daily rainfall record for midsummer.

Indiana (1989)
11 of the past 12 days brought heavy rain to at least some part of the state.