Californian Governor Gavin Newsom has declared a statewide 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.
In northern California, wildfires in the Sonoma Valley forced more than 2,000 people to evacuate, while in southern California, a conflagration in Santa Clarita drove more than 50,000 from their homes.
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.
The Kincade Fire in northern California began seven minutes after a nearby power line was damaged, but PG&E has not yet confirmed if the power glitch started the blaze.
The National Weather Service said a powerful windstorm was expected to create “potentially historic fire weather conditions” in the region.
