Californian Governor Gavin Newsom has declared a state-wide emergency as wildfires, whipped up by fierce winds, continue to sweep through the area.
Some 180,000 people in the north have been ordered to leave their homes and roads around Santa Rosa were packed with cars as people tried to flee.
Tens of thousands of homes are under threat from the wildfires.
The biggest blackouts in the state's history have already left a million people without electricity.
Power companies are trying to stop damaged cables from triggering new fires.
Another million people are expected to lose their supplies in the hours ahead.
