October 2017 Northern California wildfires , also known as the Northern California firestorm , North Bay Fires , and the Wine Country Fires 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 . 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 . Seventeen separate wildfires were reported at that time . 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 ) , 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 , causing around $ 14.5 billion ( 2017 USD ) in damages , including $ 11 billion in insured losses and $ 1.5 billion in fire suppression costs , surpassing the 1991 Oakland firestorm , which until then had been the single costliest fire on record . In addition , the Northern California fires were predicted to cost the US economy at least $ 85 billion
Atlas Fire
Atlas Fire
October 2017 Northern California wildfires