SAN FRANCISCO (AP) — California's two largest utilities were considering cutting power Monday to tens of thousands of customers as fall brings back dangerous weather conditions and the companies try to head off wildfires sparked by electrical equipment.

Pacific Gas & Electric Corp. was expected to decide by Monday evening whether controlled power outages affecting as many as 21,000 customers would be needed to ease the risk of wildfires in Northern California.

Meanwhile, Southern California Edison said it might shut off power to 41,000 customers due to forecasts calling for gusty Santa Ana winds. The utility initially estimated about 10,000 customers could be impacted.

Major increases were focused on San Bernardino and Riverside counties. Power cuts could also occur in Los Angeles and Santa Barbara counties.

Some of the most destructive blazes in the state in the past two years were started by Pacific Gas & Electric power lines.

If approved by San Francisco-based PG&E, outages could occur later in the day and affect portions of Butte, Nevada and Yuba counties in the Sierra foothills. The utility previously warned of possible shut-offs affecting an estimated 124,000 customers.

Strong winds, low humidity and warm temperatures were forecast in the region through Wednesday, and authorities issued an extreme fire danger warning for some areas.

Wind gusts could reach 50 mph (80 kph) in the northern Sierra and foothills, and between 30 to 40 mph (48 to 64 kph) in the Sacramento Valley and near the Pacific coast, said Eric Curth, a forecaster with the National Weather Service.

"Humidity levels are dropping, and winds are picking up," Curth said. "The main threat is overnight when the winds pick up in the mountains and foothills."

PG&E first cut off power preemptively last October, affecting some 87,000 customers. The move prompted complaints and demands for reimbursement.

But the utility canceled plans to shut off power ahead of a blaze that killed 86 people and nearly destroyed the town of Paradise.

An investigation by Cal Fire said transmission lines owned and operated by the utility started the Nov. 8 fire that wiped out nearly 15,000 homes.

The investigation identified a second nearby ignition site involving PG&E's electrical distribution lines that had contacted vegetation. The second fire was quickly consumed by the initial fire.

California regulators in May approved allowing utilities to cut off electricity to avoid catastrophic wildfires but said utilities must do a better job ramping up preventive efforts and educating and notifying the public, particularly people with disabilities and others who are vulnerable.

In January, PG&E sought bankruptcy protection, saying it could not afford an estimated $30 billion in potential damages from lawsuits stemming from catastrophic wildfires.

Earlier this month, PG&E agreed to pay $11 billion to insurance companies holding 85% of the claims from fires that include the November 2018 Paradise blaze.

The settlement, confirmed Monday, is subject to bankruptcy court approval.

It's important for PG&E to pull itself from bankruptcy protection because it will be a big part of a wildfire fund set up to help California's major utilities pay future claims as climate change makes wildfires more frequent and severe.

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Associated Press writers Juliet Williams in San Francisco and John Antczak in Los Angeles contributed to this report.