How Long is California’s Fire Season?
The length of the fire season in any given year in California depends on summer temperatures, rainfall, and wind, with the most fires historically occurring between May and October. However, recent data show that, due to rising temperatures and decreased rainfall, the season is beginning earlier and ending later each year, approaching a year-round fire season.1
When Does the California Fire Season End?
The fire season in California tends to end once the state receives heavy rainfall. However, the impacts of lack of
forest management mean that clean-up is often ignored, which can keep fires burning throughout the winter months.
Since wildfire thrives in hot and dry climates, drought elevates fire risk significantly. Drought leaves trees, grasses, shrubs, and soil with very little moisture, making the landscape extremely flammable.
Likewise, ongoing droughts and water diversion and mismanagement in California pose a serious threat for fire season. A recent report by the US Drought Monitor found more than 97% of the state is in severe or extreme drought, causing concern for the year ahead. When winds are paired with hot, dry weather, they pose a major fire hazard. For example, the Santa Ana winds in Southern California (also known as Diablo winds in Northern California) are strong, dry, downslope winds that blow from the mountains towards the coast and can cause wildfires to ignite and spread rapidly. Consequently, these winds reach up to 40 miles per hour and in some cases can reach up to hurricane strength, exponentially increasing in the speed of fire spread and triggering extreme destruction in short amounts of time.
As much as 90% of wildfires are started by humans. Common reasons for wildfire ignition include unattended campfires including the homeless and migrants, fallen power lines, discarded cigarettes, vehicle crashes or the use of equipment that creates sparks, like metal grinders.