LOS ANGELES — California will roast in dangerous heat through the Labor Day weekend, forecasters said Thursday, and options for cooling off may be limited by coronavirus concerns at beaches and calls for energy conservation that could limit use of air conditioning at home.

The withering hot, dry air also could create conditions ripe for more wildfires, even as blazes ignited by a lightning blitz in August continue to burn and foul the air with smoke, authorities said.

A strong ridge of high pressure building over the western U.S. is expected to send temperatures climbing Friday in Southern California and then spread the heat northward, peaking on Sunday or Monday, the National Weather Service said.

Many temperature records are likely to fall and there is a chance that some all-time record highs will be recorded, the Los Angeles region weather office said.

“These extreme max temps, combined with lows in the mid-70s to lower 80s will make Sunday one of the most hazardous in recent memory,” the office said.

With temperatures predicted to be 10 to 20 degrees above normal in California and high heat elsewhere in the West potentially limiting the availability of power to import, the manager of the state electrical grid issued a Flex Alert calling for voluntary conservation Saturday through Monday between the hours of 3 p.m. and 9 p.m.

The California Independent System Operator also ordered power generators to postpone routine maintenance and restore any out-of-service transmission lines Saturday through Monday. Cal ISO also noted that high overnight temperatures don’t allow electrical infrastructure to cool down.

The power concern follows a mid-August heat wave that strained the grid to the point where the Cal ISO ordered utilities to implement brief rolling blackouts for the first time since 2001. Officials said customers’ conservation significantly helped.

The Brewing Heat Wave Was Also Expected To Bring Another Challenge To Thousands of Firefighters

“It was an important factor indeed,” said Operations Vice President Eric Schmitt. “We’re asking for that kind of support again as we go into this weekend.”

Authorities, meanwhile, hoped to prevent a surge in COVID-19 infections that could occur if people engage in traditional Labor Day weekend activities.

Los Angeles County, the nation’s most populous, did not plan to close beaches but health authorities warned that could happen if they become too crowded, and masks will be required when people are out of the water.

Up the coast, Santa Barbara County planned to allow use of the water and active uses of the beach such as running or walking but no sunbathing. Monterey County said people could cross the sand to reach the water but otherwise barred use of beaches.

Such measures were not in place on the entire coast. Surfing mecca Huntington Beach, for example, was keeping its famous shoreline fully open.

The brewing heat wave was also expected to bring another challenge to thousands of firefighters who have been making progress on numerous wildfires, including massive complexes of multiple fires ignited by lightning last month.

“Firefighters are closely monitoring weather conditions, as extreme heat is expected over the weekend,” the California Department of Forestry and Fire Protection said in a statement.

The fires have destroyed more than 3,200 structures, including homes, and there have been eight deaths. More than 12,400 people remained evacuated Thursday.