Ferocious heat wave could bring record temperatures to California over Labor Day weekend


California will again be in the crosshairs of a potentially historic heat wave over Labor Day weekend — prompting officials to warn of heightened fire risk and urge residents to protect themselves from the dangerous temperatures.

Forecasters say the weather system will bring higher temperatures than August’s heat wave and potentially a slew of record-breaking highs.

The National Weather Service warned that “this kind of heat can be life-threatening, and people are urged to use common sense, keep hydrated and stay out of the heat and in air-conditioned locations as much as possible.”


“Of all the meteorological events that we deal with — hurricanes, tornadoes, floods — the deadliest by far is heat,” said Bill Patzert, a climatologist and local weather expert.

The bulk of the state will be in the heat wave’s throes starting Friday. Temperatures are expected to climb 15 to 20 degrees above normal — or even higher — in some areas of Southern California over the weekend.

“I’m personally going to British Columbia,” joked David Sweet, a meteorologist with the National Weather Service in Oxnard.

With the rising mercury comes a heightened risk for heat-related illnesses, and experts say it’s vital that all residents avoid unnecessary or prolonged exposure to the heat.

“We recommend that people suspend any plans they have for extended exposure to the daytime heat, because heat illnesses can strike anyone, especially young children and the elderly,” Sweet said. “So if you have any elderly neighbors, you want to check on them.”


All drive-through testing sites run by the city will be closed over the 3-day weekend, but a few pop-up testing events will be held Friday and Saturday.

Sept. 3, 2020

Aside from some northeastern areas, virtually all of California will be under an excessive heat watch or warning beginning either Friday or Saturday and continuing through Sunday or Monday.

The high temperatures will increase the threat of both power outages and large fires, unwelcome news after the one-two punch of rolling blackouts and a historic firestorm during another heat wave just weeks ago.

The California Independent System Operator, which runs the power grid for most of the state, issued a statewide flex alert Thursday — calling for voluntary electricity conservation from 3 to 9 p.m. Saturday through Monday.

If there is a silver lining, it’s that this heat wave, while intense, won’t be as long-lived as the one that broiled the state in mid-August.

Temperatures will climb Friday and top out on Saturday and Sunday before beginning to tick down Monday.

“Saturday and Sunday will be the hottest days, but Monday will still be pretty darn hot,” said Samantha Connolly, a meteorologist with the National Weather Service in San Diego.


After that, temperatures will continue to trend downward, getting closer to normal by the end of next week, according to Sweet.

“It’s a shorter period of time, but it’s going to be hotter than the last one,” he said.

On Sunday, which is expected to be the height of the heat wave in many areas, the mercury will likely top 100 degrees in downtown Los Angeles. Some of Los Angeles County’s inland valleys will surpass 110, with Woodland Hills forecast to reach 116.

Coastal areas, though cooler, could still see temperatures above 90 degrees.

“The entire region will be under an excessive heat warning at some point,” Connolly said.

Patzert said heat waves aren’t uncommon for September, though climate change has made them all the more potent.

“Looking back over the past century or so, heat waves in Southern California have gotten longer, they’ve gotten more intense and they’re more frequent,” he said. “And, of course, this is a global warming signal.”

The latest “rather extraordinary, record-strength, late-season ridge of high pressure” will likely bring “widespread record heat” to the West Coast, UCLA climate scientist Daniel Swain wrote on Twitter on Tuesday.


“Some all-time September records may be threatened,” he added.

Both Connolly and Sweet said the heat wave may rewrite the record books for a wide swath of the state. Some of the cites that could see new daily highs over the weekend include Long Beach, Camarillo, Paso Robles, Riverside, Anaheim and Escondido.

Connolly noted it is expected to be less humid than during the previous heat wave, meaning conditions, though warmer, might not feel as oppressive.

“It’s looking like most of the state is going to see this heat,” she said.

A major heat wave will be hitting California this weekend, complicating firefighting efforts and potentially bringing more challenges to the electrical grid.

Sept. 3, 2020

To reduce strain on the electrical grid, the California ISO recommends residents hold off on using major appliances, turn off unnecessary lights, close blinds and drapes and set thermostats to 78 degrees while the flex alert is in effect.

“In some places they’re taking down statues ... but here in L.A. what we should do is build a statue for Mr. Carrier,” Patzert said, referencing Willis Carrier, the inventor of modern air conditioning.

Forecasters also said residents need to avoid the heat as much as possible.

While outside, officials recommend wearing light-colored, lightweight clothing and using a hat or umbrella for shade. Children and pets also should never be left in cars, and residents should keep an eye out for symptoms of heat-related illnesses — including vomiting, pale and clammy skin and high body temperature.

Sweet also said it’s important to drink plenty of liquids.

Given the upcoming holiday weekend, he clarified, “we recommend water, not alcohol. Alcohol will dry you out.”


Aside from being a “silent killer,” Patzert said heat is also a socioeconomic one, as it disproportionately affects those who don’t have air conditioning or can’t afford to run it.

“Of course, all this is exacerbated here in the time of coronavirus because many of the poorer sections of the city have to resort to cooling centers — but how do you do that in the middle of a coronavirus epidemic?” he said.

A number of cooling centers will be available in Los Angeles County during the heat wave, and officials said Thursday that those locations “will operate in compliance with physical distancing and other COVID-19 safety criteria.”

Centers will be available at the following locations:

  • Valleydale Park, 5525 North Lark Ellen Ave., noon to 6 p.m. Friday through Sunday
  • Buena Vista Library, 300 North Buena Vista St., noon to 6 p.m. Friday through Monday
  • El Monte Community Center, 3130 Tyler Ave., noon to 6 p.m. Saturday and Sunday
  • Griffith Manor Park, 1551 Flower St., 10 a.m. to 6 p.m. Friday and Tuesday
  • Pacific Community Center, 501 South Pacific Ave., 10 a.m. to 6 p.m. Saturday through Monday
  • Crowther Teen & Family Center, 241 West Dawson Ave., 10 a.m. to 6 p.m. Friday through Monday
  • Museum of Art and History, 665 West Lancaster Blvd., 10 a.m. to 5 p.m. daily
  • Sunshine Park, 515 Deepmead Ave., noon to 6 p.m. Friday through Sunday
  • Salazar Park, 3864 Whittier Blvd., noon to 6 p.m. Friday through Sunday
  • Chimbole Cultural Center, 38350 Sierra Highway, noon to 6 p.m. Thursday through Tuesday
  • Robinson Park, 1081 North Fair Oaks Ave., 9 a.m. to 6 p.m. Friday through Monday
  • Quartz Hill Library, 5040 West Avenue M-2, noon to 6 p.m. Wednesday through Sunday
  • Senior Center / Community Center, 201 East Bonita Ave., 10 a.m. to 6 p.m. Thursday through Sept. 10
  • Las Palmas Park, 505 South Huntington St., 10 a.m. to 7 p.m. Friday through Tuesday
  • Stevenson Ranch Library, 25950 The Old Road, noon to 6 p.m. Wednesday through Sunday
  • Ken Miller Recreational Center, 3341 Torrance Blvd., noon to 6 p.m. Saturday through Sunday