Driven by gusty winds, the Kincade fire north of San Francisco was still growing on Sunday, and power was shut off to millions of customers to prevent more outbreaks.

By Lauren Hepler and Nicholas Bogel-Burroughs

Pacific Gas and Electric warns of a new round of preventive blackouts that may come during the week.

Here’s what you need to know:

• The governor has declared a state of emergency.
• About 180,000 people have been ordered to evacuate.
• Power shut-offs have begun that could affect nearly 3 million.
• For those with homes in the fire’s path, anxiety and hope.
• Two hospitals had to relocate hundreds of patients.

The governor has declared a state of emergency.

Gov. Gavin Newsom of California declared a state of emergency on Sunday, saying the high winds that have been fueling the blazes in the state were “unprecedented” and pleading with people in evacuation zones to flee.

The Kincade fire, the largest of more than a dozen wildfires now active up and down the state, has burned more than 30,000 acres since Wednesday night in Sonoma County, north of San Francisco, and was only 10 percent contained on Sunday. Local authorities have ordered more than 180,000 people to evacuate from its path.

“We are deploying every resource available, and are coordinating with numerous agencies as we continue to respond to these fires,” Mr. Newsom said, noting that more than 3,000 firefighters were battling the Kincade fire alone.

Nearly 1,000 more firefighters are working to contain the Tick fire in Southern California, which was burning more than 4,600 acres on Sunday morning and threatening thousands of homes in Los Angeles County.

At least three new vegetation fires were sparked on Sunday, one covering 600 acres in Tehama County, 100 miles north of the Kincade fire, and one affecting 200 acres near Vallejo in the Bay Area, where embers apparently jumped about a mile across the Carquinez Strait to start another blaze on the far side. That fire threatened the campus of the California State University Maritime Academy.

Californians far beyond the immediate areas of the fires are being affected, as one of the state’s main power utilities, Pacific Gas and Electric, has shut off power to nearly 1 million homes and businesses to prevent its lines and equipment from sparking new fires in the dry, windy conditions. Many people who fled the Kincade fire were leaving behind dark houses where the electricity had already been shut off.

“It is critical that people in evacuation zones heed the warnings from officials and first responders, and have the local and state resources they need as we fight these fires,” Mr. Newsom said.