Fire officials said on Thursday the tally could rise further in the eight counties which have been affected by the fires.
In Sonoma County alone, where entire neighborhoods have been destroyed, hundreds of people are still unaccounted for.
The fires have swept through California’s wine country, leaving thousands of people homeless and burning over 190,000 acres (76,000 hectares) of land.
Firefighters said gusty winds and dry conditions have hampered their efforts to contain the fires, which began on Sunday. Some 8,000 firefighters were battling 20 blazes as of Thursday.
“What this means is that our fires will continue to burn erratically,” California fire chief Ken Pimlott told a press conference. “They have the potential to shift in any direction at any time.
“We are a long way from being done with this catastrophe,” he said.
On Tuesday, President Donald Trump declared a major disaster in California, releasing funding and resources to fight the catastrophe.
Forest fires are common in the western United States during hot months, but few have claimed as many lives as this week’s blaze.