SAN FRANCISCO (AP) — Large swaths of California had no electricity Monday as utilities tried to prevent the chance of their equipment sparking wildfires while the fire-weary state was buffeted by powerful winds and dangerously dry weather conditions.

About 300,000 power customers — estimated at more than 1 million people — were in the dark as officials issued warnings for what could be the strongest winds for California this year.

North of San Francisco, a Mount St. Helena weather station recorded a hurricane-force gust of 89 mph (143 kph) late Sunday and sustained winds of 76 mph (122 kph).

Winds had calmed slightly by Monday morning but still topped 60 mph (97 kph), the National Weather Service said.

“While this is less than what we saw earlier, these winds are still strong and dry conditions prevail,” the agency said on Twitter.

Winds reached 50 mph (80 kph) early Monday at lower elevations across the San Francisco Bay Area, where tens of thousands had their electricity turned off. Officials extended a red flag extreme fire danger warning through 5 p.m. Tuesday for the region's eastern and northern mountainous areas.

A second round of strong gusts is predicted to sweep through the same areas Monday night, forecasters warned.

Scientists have said climate change has made California much drier, meaning trees and other plants are more flammable. October and November are traditionally the worst months for fires, but already this year 8,600 wildfires in the state have scorched a record 6,400 square miles (16,600 square kilometers) and destroyed about 9,200 homes, businesses and other buildings. There have been 31 deaths.

The electricity shutdowns marked the fifth time this year that Pacific Gas & Electric, the nation’s largest utility, has cut power to customers to reduce the risk of downed or fouled power lines or other equipment could ignite blazes during bone-dry weather conditions and gusty winds.

On Sunday, the utility shut off power to 225,000 customers in Northern California and later did so for another 136,000 customers in 36 counties.

“This event is by far the largest we’ve experienced this year, the most extreme weather,” said Aaron Johnson, the utility’s vice president of wildfire safety and public engagement. “We’re trying to find ways to make the events less difficult.”

Firefighting crews quickly contained small fires that broke out Sunday in Sonoma and Shasta counties. The causes were under investigation.

The National Weather Service predicted winds in Southern California of up to 35 mph (56 kph) in lower elevations and more than 70 mph (113 kph) in mountainous areas. Officials were worried that any spark could turn into flames sweeping through tinder-dry brush and forestland.

The conditions could equal those during devastating fires in California’s wine country in 2017 and last year’s Kincade Fire that devastated Sonoma County north of San Francisco last October, the National Weather Service said. Fire officials said PG&E transmission lines sparked that fire, which destroyed hundreds of homes and caused nearly 100,000 people to flee.

Weather conditions shifted in Northern California on Sunday, with humidity dropping and winds picking up speed, said Scott Strenfel, PG&E's senior meteorologist. He said another round of winds is expected Monday night.

Extreme fire danger moved into Southern California late Sunday following cooler temperatures and patchy drizzle over the weekend.

The Southern California Edison utility said it was considering preventative safety power outages for 71,000 customers in six counties starting Monday, with San Bernardino County to the east of Los Angeles potentially the most affected.

Los Angeles County officials urged residents to sign up for emergency evacuation notices and to be prepared to stay with family or friends in less risky areas. Local fire officials boosted staffing as a precaution.

“The reality is come midnight and through Tuesday we’re going to be in the most significant red flag conditions we’ve had this year,” said Kevin McGowan, director of the county’s Office of Emergency Management.

Many of this year’s devastating fires were started by thousands of dry lightning strikes, but some remain under investigation for potential electrical causes. While the biggest fires in California have been fully or significantly contained, more than 5,000 firefighters remain committed to 20 blazes, state fire officials said.

PG&E officials said the planned outages are a safety measure and understood they burden residents, especially with many people working from home and their children taking classes online because of the coronavirus pandemic.

Sheriff Kory Honea of Butte County in Northern California said he’s concerned about residents in foothill communities during the blackouts because cellular service can be spotty and it’s the only way many stay informed when the power is out.

“It is quite a strain on them to have to go through these over and over and over again,” he said.

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Taxin reported from Orange County, California. Associated Press writer Christopher Weber in Los Angeles contributed to this report.