Welcome to another heat wave. Triple-digit temperatures on tap for Southern California

Los Angeles, California-Sept 5, 2022-Bill Morris of Wilmington, CA, prepares his dingy Sunburn for a paddle at Cabrillo Way Marina on Sept. 5, 2022. As the temperature remains high on Labor Day 2022, people had to the waterfront for relief, Sept. 5, 2022. (Carolyn Cole / Los Angeles Times)
Bill Morris paddles at Cabrillo Way Marina in San Pedro on Sept. 5. (Carolyn Cole / Los Angeles Times)

The first days of fall will be met with increasing temperatures as another heat wave makes it way to Southern California.

Thankfully, temperatures this time won't be quite as extreme as the record-smashing heat wave that broiled California at the start of September, but they will be noticeably higher after the recent cool respite.

In the Los Angeles area, the mercury will start to climb Friday, with up to 100 degrees possible in valley areas and 95 degrees in the mountains and deserts, according to the National Weather Service. But peak heat will come Sunday through Tuesday, when valley areas could see temperatures as high as 106 degrees and mountains and deserts could reach 100.

"We're not expecting it to be as warm or as long" as the previous heat wave, said Mike Wofford, a meteorologist with the weather service in Oxnard. "It won't be nearly as bad, so that's a good thing."

However, temperatures will be 5 to 10 degrees above normal through Saturday, then 10 to 20 degrees above normal Sunday through Tuesday.

The warmth won't be limited to Los Angeles, either.

In the San Diego area, the heat will peak Monday and Tuesday, forecasters said. Temperatures in the Inland Empire are expected to exceed 100 degrees, while inland Orange County and San Diego could reach the mid- to upper 90s. Palm Springs and Thermal could climb as high as 108 degrees.

Central California will also see temperatures about 6 to 10 degrees above normal for the time of year, with Bakersfield, Hanford and Fresno all expected to peak at around 95 degrees. In the Bay Area, temperatures could max out around 95 degrees on Saturday.

Wofford said the heat wave is being driven by a strong ridge of high pressure and a bit of offshore flow.

"So instead of our usual sea breeze, we get wind that comes from the east, so it kind of shuts off our usual 'air-conditioning effect' that keeps us cooler," he said of the Los Angeles area. "When we have those factors converging, that's when we tend to warm up."

The heat wave will increase the risk for heat illness, the weather service said. Residents are advised to stay hydrated and seek shade as much as possible, and never leave kids or pets in vehicles unattended.

The weather service is also reminding people to check up on those who are sick, elderly or without air conditioning, as they tend to be the most vulnerable during heat events. A Times investigation last year found that heat deaths are chronically undercounted in California, despite the fact that extreme heat is one of the deadliest consequences of climate change.

Earlier this month, Gov. Gavin Newsom signed into law a bill that will require the California Environmental Protection Agency to develop an extreme heat ranking system by 2025, the first such ranking system in the nation. As with hurricanes, the system will rank severity and health dangers of heat waves to help local governments take action.

But while some may not welcome another round of warmth after the last heat wave, Wofford noted that the conditions are not all that unusual for the time of year. In fact, he said, the highest temperature ever recorded in downtown Los Angeles — 113 degrees — occurred at the end of September in 2010.

"It would be unusual not to have heat waves this time of year," he said.

As for whether it's the last of the heat for 2022 — that's also not likely, he said.

"We're just getting into Santa Ana season, so usually we get some pretty hot temperatures with them too," he said. "We're really not out of the woods yet. Honestly, we're really not out of the woods ever, because we can get heat waves any time of the year. But in September, October, we're still in the thick of it."

This story originally appeared in Los Angeles Times.