Responding to the emergency, President Donald Trump issued a major disaster declaration to provide federal assistance. Gov. Gavin Newsom said in a statement that the declaration will also help people in counties affected by the fires with crisis counseling, housing and other social services.

Two clusters of wildfires in the San Francisco Bay Area grew to become the second- and third-largest wildfires in recent state history by size. Light winds and cooler and more humid nighttime weather helped fire crews make progress on those fires and a third group of fires south of San Francisco ahead of the forecast of warm, dry weather, erratic wind gusts and lightning, state fire officials said.

The National Weather Service issued a red flag warning of high fire danger across the Bay Area and along the Central Coast, beginning from Sunday morning to Monday afternoon.

"The worst is not behind us. We are in a battle rhythm," California Department of Forestry and Fire Protection (Cal Fire) Chief Thom Porter tweeted.