List of California wildfires

This is a partial and incomplete list of wildfires in the US state of California. California has dry, windy, and often hot weather conditions from spring through late autumn that can produce moderate to severe wildfires. Pre-1800, when the area was much more forested and the ecology much more resilient, 4.4-11.9 million acres (1.8-4.8 million hectares) of forest and shrubland burned annually.^[1] California land area totals 99,813,760 or roughly 100 million acres, so since 2000, the area that burned annually has ranged between 90,000 acres, or 0.09%, and 1,590,000 acres, or 1.59% of the total land of California.^[2] During the 2020 wildfire season alone, over 8,100 fires contributed to the burning of nearly 4.5 million acres of land.

Since the early 2010s, wildfires in California are growing more dangerous because of the accumulation of wood fuel in forests, higher population, and aging and often poorly maintained electricity transmission and distribution lines, particularly in areas serviced by Pacific Gas and Electric.^[3][4][5] United States taxpayers pay about US$3 billion a year to fight wildfires, and big fires can lead to billions of dollars in property losses.^[6] At times, these wildfires are fanned or made worse by strong, dry winds, known as Diablo winds when they occur in the northern part of the state and Santa Ana winds when they occur in the south. However, from a historical perspective, it has been estimated that prior to 1850, about 4.5 million acres (17,000 km²) burned yearly, in fires that lasted for months, with wildfire activity peaking roughly every 30 years, when up to 11.8 million acres (47,753 km³) of land burned.^[7][8] The much larger wildfire seasons in the past can be attributed to the policy of Native Californians regularly setting controlled burns and allowing natural fires to run their course, which prevented devastating wildfires from overrunning the state.^[7]

More than 350,000 people in California live in towns sited completely within zones deemed to be at very high risk of fire. In total, more than 2.7 million people live in "very high fire hazard severity zones", which also include areas at lesser risk.^[9]

On lands under CAL FIRE's jurisdictional protection (i.e. not federal or local responsibility areas), the majority of wildfire ignitions since 1980 have been caused by humans. The four most common ignition sources for wildfires on CAL FIRE-protected lands are, in order: equipment use, powerlines, arson, and lightning.^[10]

A 2023 study found that these wildfires are affecting the California ecosystem and disrupting the habitats.^[11][12] It found that in the 2020 and 2021 fire seasons 58% of the area affected by wildfires occurred in those two seasons since 2012.^[11][13] These two fires destroyed 30% of the habitat of 50 species as well as 100 species that had 10% of their habitats burn. 5-14% of the species' habitats burned at a "high severity."^[14][15]