By the end of 2021, a total of 7,396 wildfires burned across the U.S. state of California. Approximately 3,629 structures were damaged or destroyed by the wildfires, and three firefighters died during the wildfire season.

The wildfire season in California experienced an unusually early start amid an ongoing drought and historically low rainfall and reservoir levels. In January 2021 alone, 297 fires burned on nonfederal land according to the California Department of Forestry and Fire Protection, which is almost triple the number of fires and more than 20 times the acreage of the five-year average for January. The January fires were exacerbated by unseasonably strong Santa Ana winds, and some of them burned in the same areas as previous fires like the CZU Lightning Complex.

The long term trend is that wildfires in the state are increasing due to climate change in California. The 2021 wildfire season was exceptionally severe in California, although it did not approach the extent of the previous year's wildfire season, which was the largest season in the state's recorded history. By July 11 of that year, more than three times as many acres had burned compared to the previous year, with drought, extreme heat, and reduced snowpack contributing to the severity of the fires. The state also faced an increased risk of post-wildfire landslides.

As of August 18, 2021, the state of California was facing "unprecedented fire conditions" as multiple fires including the Dixie Fire, McFarland Fire, Caldor Fire, and others, raged on. The USDA Forest Service temporarily closed all of California's national forests at the end of August to mitigate the impact of potential fires.

On October 18, 2021, much of the state—particularly Northern California, where the majority of the significant fires had been located—received its first major precipitation since the start of the wildfire season. This significantly lowered wildfire risk in the region.

Background

The timing of "fire season" in California is variable, depending on the amount of prior winter and spring precipitation, the frequency and severity of weather such as heat waves and wind events, and moisture content in vegetation. Northern California typically sees wildfire activity between late spring and early fall, peaking in the summer with hotter and drier conditions. Occasional cold frontal passages can bring wind and lightning. The timing of fire season in Southern California is similar, peaking between late spring and fall. The severity and duration of peak activity in either part of the state is modulated in part by weather events: downslope/offshore wind events can lead to critical fire weather, while onshore flow and Pacific weather systems can bring conditions that hamper wildfire growth.

Impact

PG&E and other utility companies preemptively spent billions of dollars to reduce the risk of wildfires and avoid an year similar to the previous year's fire season. Firefighters have also set prescribed fires to prevent other fires burning. During evacuations from the Lava Fire, an illegal marijuana farmer was shot and killed by police after brandishing a firearm at authorities, while "defending his farm".

A 2023 study found that these wildfires are affecting the California ecosystem and disrupting the habitats. It found that in the 2020 and 2021 fire seasons 58% of the area affected by wildfires occurred in those two seasons since 2012. 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."

List of wildfires

The following is a list of fires that burned more than , or produced significant structural damage or casualties.

NameCounty AcresStart dateContainment dateNotesRefOwensKern1,512Unknown causeSouthernSan Diego5,366 4 structures destroyedPalisadesLos Angeles1,202Human-caused, suspected arson; 1 firefighter injuredSargentsMonterey1,100Unknown causeSierraSan Diego1,000 WillowMonterey2,877Unknown causeMojaveSan Bernardino2,490Caused by lightningNettleTulare1,265 HenryAlpine1,320Caused by lightningLavaSiskiyou26,409Caused by lightning; 23 structures destroyed; 1 structure damaged; 6 firefighters injuredShellKern1,984Caused by a car fireTennantSiskiyou10,580Unknown cause; 9 structures destroyedSaltShasta12,660Caused by hot material falling off of a vehicle; 43 structures destroyedEast ForkAlpine1,136Caused by lightningBeckwourth ComplexPlumas, Lassen105,670Caused by lightning; includes the Dotta Fire and the Sugar Fire; 148 structures destroyed; 23 structures damagedTamarackAlpine, Mono, Douglas (NV)68,637Caused by lightning; 25 structures destroyed; 7 structures damagedJuniperModoc1,011Unknown causeRiverMariposa, Madera9,656Unknown cause; 12 structures destroyed; 2 structures damagedDexterMono2,965Caused by lightningDixieButte, Lassen, Plumas, Shasta, Tehama963,309Caused by contact between tree and power lines; 1,329 structures destroyed; 95 structures damaged; 1 firefighter fatality; 3 firefighter injuries. Merged with the Fly Fire on July 24. Second-largest wildfire and the largest single (non-complex) wildfire in recorded California historyPeakKern2,098Unknown cause; 1 structure destroyedFlyPlumas4,300Unknown cause; merged with the Dixie Fire on July 24McFarlandShasta, Tehama, Trinity122,653Caused by lightning; 46 structures destroyed; 1 structure damaged; 6 firefighters injuredMonumentTrinity223,124Caused by lightning; 52 structures destroyed; 3 structures damagedRiver ComplexSiskiyou, Trinity199,359Caused by lightning; 122 structures destroyed; 2 structures damaged; consists of 22 fires, of which the largest are the Haypress Fire, the Summer Fire, and the Cronan FireMcCashSiskiyou94,962Caused by lightning; 1 firefighter fatalityTiltillTuolumne2,323Caused by lightningAntelopeSiskiyou145,632Caused by lightning; 18 structures destroyed; 4 structures destroyedRiverNevada, Placer2,619Unknown cause; 142 structures destroyed; 21 structures damaged; 4 injuriesCaldorEl Dorado, Amador, Alpine221,835Unknown cause; 1,003 structures destroyed; 81 structures damaged; 5 injuriesWalkersTulare8,777Caused by lightningFrenchKern26,535Human-caused; 49 structures destroyed; 6 structures damaged; 1 firefighter fatalitySouthSan Bernardino819Unknown cause; 17 structures destroyedChaparralSan Diego, Riverside1,427Unknown cause; 3 structures destroyedKnobHumboldt2,421Unknown causeWindyTulare97,528Caused by lightning; 128 structures destroyed; 4 injuriesKNP ComplexTulare88,307Caused by lightning; includes the Colony Fire and the Paradise Fire; 4 structures destroyed; 1 structure damagedFawnShasta8,578Suspected arson; 185 structures destroyed; 26 structures damaged; 3 injuriesAlisalSanta Barbara16,970Unknown cause; 12 structures destroyed

Wildfires listed by month

MonthNumber of wildfiresJanuary10February0March3April10May24June51July36August27September14October9November1December0 Source Cal Fire incidents 2021

Gallery of maps

See also

List of California wildfires

Notes

References

External links Current fire information — California Department of Forestry and Fire Protection (CAL FIRE)