State of emergency as California fires spread

California's governor declared a state-wide emergency on Sunday as a huge wind-fuelled blaze forced evacuations and massive power blackouts, threatening tourist towns in the state's famed Sonoma wine region.

The so-called Kincade Fire, north of San Francisco, spread to 30,000 acres overnight, with only 10 per cent containment by early afternoon Sunday, state fire authorities said.

The blaze, the largest of more than a dozen wildfires burning throughout the state, has destroyed dozens of homes and wineries, including the iconic Soda Rock Winery built in 1869.

"We've seen the news. We are devastated," the owners said in a Facebook message, adding that all staff at the winery were safe.

The Kincade Fire -- the most devastating in California this year -- ignited on Wednesday and spread quickly thanks to powerful wind gusts up to 145 kilometers per hour.

Governor Gavin Newsom declared a statewide emergency on Sunday due to the "unprecedented" high winds that have led to the fires.

"We are deploying every resource available, and are coordinating with numerous agencies as we continue to respond to these fires," Newsom said in a statement. "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."