California`s previous record burn area was nearly 2 million acres in 2018 when the state had its most deadly and destructive wildfire that killed at least 85 civilians and destroyed nearly 19,000 structures in and around the mountain town of Paradise. 

source https://zeenews.india.com/world/more-than-4-million-acres-land-burned-due-to-california-fire-in-2020-breaks-all-record-2314821.html