The October 2017 Northern California wildfires, also known as the Northern California firestorm, North Bay Fires, and the Wine Country Fires[7] were a series of 250 wildfires that started burning across the state of California, United States, beginning in early October. Twenty-one became major fires that burned at least 245,000 acres (99,148 ha).[1]
The wildfires broke out throughout Napa, Lake, Sonoma, Mendocino, Butte, and Solano Counties during severe fire weather conditions, effectively leading to a major red flag warning for much of the Northern California area. Pacific Gas and Electric reported that red flag conditions existed in 44 of the 49 counties in its service area.[8] Seventeen separate wildfires were reported at that time.[9] These fires included the Tubbs Fire (which grew to become the most destructive wildfire in the history of California up until that time - fires in 2018 were more destructive),[1][10] the Atlas Fire, Nuns Fire, and others.
These wildfires were also the most destructive ones of the 2017 California wildfire season. The October 2017 fires were the costliest group of wildfires on record at the time, causing around $14.5 billion (2017 USD) in damages, including $11 billion in insured losses and $1.5 billion in fire suppression costs,[5][6] surpassing the 1991 Oakland firestorm, which until then had been the single costliest fire on record.[11][12] In addition, the Northern California fires were predicted to cost the US economy at least $85 billion.[13] In 2018, the Camp Fire surpassed the October 2017 fires to become the single-costliest fire on record, causing an estimated $16.5 billion (2018 USD) in property damage.[14]
Owing to the extreme conditions, shortly after the fires ignited on October 8 and 9, they rapidly grew to become extensive, full-scale incidents spanning from 1,000 acres (400 hectares) to well over 20,000 acres (8,100 ha), each within a single day. By October 14, the fires had burned more than 210,000 acres (85,000 ha)[1] while forcing 90,000 people to evacuate from their homes.[15] In total, the Northern California fires killed 44 people[2] and hospitalized at least 192 others,[16][3] making this one of the deadliest wildfire events in the United States during the past century.[17][18][1][19][20]