SAN FRANCISCO >> The state’s largest utility said it will go ahead with widespread blackouts affecting nearly half a million people starting today as dangerous fire weather returns to California.

Pacific Gas & Electric Co. said it would begin precautionary power shutoffs in the afternoon affecting nearly 180,000 homes and businesses in portions of 17 counties, mostly in the Sierra foothills and north of the San Francisco Bay Area.

The outages will last about 48 hours, the utility said.

Meanwhile, Southern California Edison said it could cut power Thursday to more than 160,000 customers in six counties and San Diego Gas & Electric was warning of power shutoffs to about 24,000 customers.

The utilities say they’re concerned that winds forecast to top 60 mph could throw branches and debris into power lines or topple them, sparking wildfires.

PG&E cut power to more than 2 million people across the San Francisco Bay Area in rolling blackouts from Oct. 9-12, paralyzing parts of the region in what was the largest deliberate blackout to prevent wildfires in state history. Schools and universities canceled classes and many businesses were forced to close.

PG&E’s new warning just two weeks later prompted feelings of frustration and resignation among some residents and business owners and renewed rushes to stock up on batteries and other emergency supplies.

Love Birds Coffee & Tea in the old Gold Rush town of Placerville lost about $6,000 in the last outage — a huge chunk of change for a mom-and-pop business and a hit from which the store hasn’t yet recovered, owner Garrett Sanders said.

“Working this close to the last outage is going to be a true trial by fire,” he said.

This time, Sanders plans to brew coffee and stock up on handmade pastries before the shut-off, then sell them on the sidewalk — along with a smile.

“It’s going to be a sober morning for people waking up without their coffee,” he said. “We can’t do, like, all of our espressos and milk-based drinks but we’ll have coffee. It’ll be better than nothing.”

Sanders said he is sympathetic to the argument that the outages are designed to prevent wildfires, especially since a dozen people settled in Placerville after they were burned out of the town of Paradise by a fire that killed scores of people last year.

“Of course, none of us wants the devastation” of a wildfire, Sanders said, “but I think the measures that PG&E is taking are to the ultimate extreme.”

California Gov. Gavin sent a sharply worded letter Tuesday to Bill Johnson, PG&E’s CEO, blaming the unprecedented mass outage earlier this month on the company’s failure to maintain and upgrade its equipment.

“I believe the unacceptable scope and duration of the previous outage — deliberately forcing 735,000 customers to endure power outages — was the direct result of decades of PG&E prioritizing profit over public safety,” Newsom wrote, referring to the number of businesses and households affected, not the total number of people.

PG&E says the shutdowns are not about money.

The only goal “is to prevent a catastrophic wildfire,” Johnson said in a Tuesday briefing.