Wildfires raged unchecked across parts of the western U.S. on Wednesday amid gusty and dry conditions, but forecasters said some weather relief was in sight that could help firefighters overwhelmed by the blazes.

In California, winds stoked unprecedented numbers of fires that have forced rescues and evacuations. In Washington, more acres burned in a single day than firefighters usually see all year. Fires also forced people to flee in Oregon and Idaho.

A temperature plunge of as much as 60 degrees (15 Celsius), caused by a dramatic intrusion of polar air, helped slow wildfires that spread in Colorado and Montana.

“The significantly colder airmass is helping reduce critical fire conditions across the West, however most of West coastline and adjacent counties have Red Flag warnings in effect for part of today,” the National Weather Service said. A warning is issued when conditions combine to produce an increased risk of fire danger.

Diminishing winds were possible by Thursday, “bringing some relief to the ongoing fires and fire weather threat,” forecasters said.

A massive cloud of smoke covered much of California on Wednesday, dimming the sun to an eerie orange glow over San Francisco.

About 125 miles (200 kilometers) to the northeast, winds fanned a huge fire in the Sierra Nevada foothills and forced authorities to order early morning evacuations and warn other residents to be ready to leave.

The area is not far from the town of Paradise, where 85 people were killed by a fire two years ago, and Oroville Dam, where failing spillways forced a massive evacuation in 2017.

On Tuesday, flames overtook 14 firefighters who had to delploy last-resort emergency shelters and destroyed a fire station in Los Padres National Forest on California’s central coast. They suffered burns and smoke inhalation, and three were flown to a hospital in Fresno, where one was in critical condition, the U.S. Forest Service said.

Helicopters have been used in recent days to rescue hundreds of people stranded in the burning Sierra National Forest, where a fire has destroyed 365 buildings, including at least 45 homes. About 5,000 buildings were threatened, fire officials said.

Flames threatened the foothill community of Auberry between Shaver Lake and Fresno.

In Southern California, fires burned in the mountains of Los Angeles, San Bernardino and San Diego counties, with the potential for the region’s notorious Santa Ana winds to push flames out of wilderness and into communities.

People in a half-dozen foothill communities east of Los Angeles were being told to stay alert because of a fire in the Angeles National Forest.

“The combination of gusty winds, very dry air, and dry vegetation will create critical fire danger,” the National Weather Service warned.

The U.S. Forest Service on Monday closed all eight national forests in the southern half of the state and shutter campgrounds statewide.

More than 14,000 firefighters are battling fires in California Two of the three largest blazes in state history are burning in the San Francisco Bay Area, though they are largely contained after burning for three weeks.

The state has set a record with nearly 2.3 million acres (930,800 hectares) burned this year and the worst part of the wildfire season is only beginning.

“It’s extraordinary, the challenge that we’ve faced so far this season,” Gov. Gavin Newsom said.

The threat of winds tearing down power lines or hurling debris into them and sparking a wildfire prompted Pacific Gas & Electric, the state’s largest utility, to shut off power to 172,000 customers in Northern California. More outages were expected Wednesday, with power not expected to be completely restored until Wednesday night.

(AP)