Nearly a million people in California will be blacked out as powerful winds threaten to knock down electric wires and spark further fires.
A California power company says it will shut off power to around 940,000 customers across the north of the US state as powerful winds threatened to knock down electric wires and spark further fires.
"Predictive data models indicate the weather event could be the most powerful in California in decades," Pacific Gas & Electric said in a Friday news release, adding that winds were predicted to gust over 113km/h.
"Winds of this magnitude pose a higher risk of damage and sparks on the electric system and rapid wildfire spread."
The utility said it would shut off power in phases across 36 counties, starting at 2 pm on Saturday (0900 AEDT). The blackouts could last until midday on Monday.
California Governor Gavin Newsom said the outages were "unacceptable."
"We are going to do our best to get through these high-wind events and work through Saturday, Sunday into Monday and get these lights back on and do everything in our power to make sure PG&E is never in a position where they're doing this to us again," Newsom said in a video posted on Twitter.
The largest wildfire is currently raging in northern California's Sonoma County, where 50,000 residents were ordered to evacuate on Saturday.
Fire officials said the evacuation orders may be the largest in the region's history, the Los Angeles Times reported.
'Story about greed'
A number of bushfires are also raging in the northern part of the state. The most serious - the Kincade Fire - broke out late Wednesday in the Sonoma wine region, also prompting evacuations.
The high risk of fires has led to pre-emptive power cuts to thousands of customers and prompted Governor Gavin Newsom to declare a state of emergency in Sonoma and Los Angeles counties.
Mr Newsom traveled to Sonoma on Friday to survey areas impacted by the Kincade Fire which has grown to around 23,700 acres and was only five percent contained as of Friday evening.
The blaze, which is burning in remote steep terrain, has destroyed nearly 50 structures and forced the evacuation of the entire community of Geyserville and nearby vineyards.
Mr Newsom told reporters the area looked like a "war zone," with homes and vehicles destroyed.
Residents said they barely had time to gather their belongings as the ferocious fire approached their homes.
"We looked up the hill and couldn't believe what we saw," ranch owner Dwight Monson, 68, told the Los Angeles Times, saying the fire moved 22 kilometres in five hours before destroying four homes and a barn on his property.
The state's largest utility, Pacific Gas & Electric Co., warned that millions of people in northern and central parts of the state could have their power cut off during the weekend given the high risk of fire.
The company has come under intense scrutiny after it reported Thursday that even though power to nearly 28,000 customers in Sonoma County had been shut down on Wednesday, some of the high-voltage transmission lines were still operating when the fire broke out.
The same type of equipment was responsible for the state's deadliest bushfire ever - the Camp Fire in 2018 which killed 86 people.
PG&E, which filed for bankruptcy earlier this year, has been blamed for several other fires in the state in recent years.
Mr Newsom hit out at the company on Friday, saying it had put "profits over the people of California for too long."
The governor said it was "infuriating beyond words" that a state as innovative as California has to see these types of blackouts, adding that the frequency of fires could not only be blamed on climate change.
"It's about dog eat dog capitalism meeting climate change," he said, referring to PG&E. "It's a story about greed and they need to be held accountable."
Instense fires also erupted over the border in Mexico's Baja California state, where local civil protection authorities said on Friday that three people had been killed and over 150 homes destroyed.
The director of Civil Protection, Antonio Rosquillas, explained that the municipality of Tecate, bordering the United States, was worst hit.