Rising temperatures prompt excessive-heat warnings this week for much of Southern California

LOS ANGELES, CA - NOVEMBER 11: Several trails feed into the Mt Hollywood Trail leading to the peak of Mount Hollywood at 1,625 ft which is the second tallest peak in Griffith Park. The trails provide amazing views of the Griffith Observatory, downtown Los Angeles, the Hollywood Sign and views to the Pacific Ocean on clear days. much more. There are many trails that lead to Mt. Hollywood, but a favorite trail begins near the Ferndell Nature Area. Griffith Park on Thursday, Nov. 11, 2021 in Los Angeles, CA. (Al Seib / Los Angeles Times).
An excessive heat warning is forecast for a large swath of Southern California beginning Monday, according to the National Weather Service. (Al Seib/Los Angeles Times)

Temperatures are expected to rise by as much as 16 degrees above normal early this week, elevating the risk of wildfires and heat-related illnesses as another blistering August heat wave hits Southern California.

Temperatures will range from 90 to 109 degrees in valley, inland and mountain areas on Monday and Tuesday, prompting excessive heat warnings and advisories for a large swath of the region, including Los Angeles, Ventura, Riverside, San Bernardino and San Diego counties

Health officials are urging the public to take precautions to protect themselves against heat exhaustion and heat stroke by drinking plenty of water and either staying indoors or seeking out cooling centers with air conditioning. Los Angeles County cooling center locations, including those that are pet friendly, can be found by calling 311 or visiting https://ready.lacounty.gov/heat/.

Of particular concern are those "who are especially vulnerable to the harmful effects of high temperatures, including children, the elderly those who are sick or have chronic conditions, pregnant women, those who live alone, and pets,” Dr. Muntu Davis, county health officer for the L.A. County Department of Public Health, said in a statement. "High temperatures are not just an inconvenience; they can be dangerous and even deadly."

The latest heat wave comes on the heels of Tropical Storm Hilary, which dropped record rainfall across Southern California and caused significant flooding in inland areas. But those downpours won't mitigate the fire risks posed by scorching temperatures, because dry vegetation and brush that fuel wildfires are typically not receptive to moisture this time of year, said meteorologist Mike Wofford, of the National Weather Service.

On Sunday, Los Angeles County was expected to see highs in the mid-80s to mid-90s. But gusty sundowner winds are expected Sunday night and Monday night, further elevating dangerous fire conditions.

Wofford said the heat warnings and advisories issued for Monday and Tuesday should be similar to the high temperatures the region experienced in the middle of August.

"I think we're going to see similar numbers," Wofford said. "It will be a little warmer for coastal areas this time around because we don't have as much of the marine layer we did before. Valleys will probably be within a few degrees of the last [heat wave]."

By Wednesday, temperatures are expected to drop down to upper 90s to lower 100s in valley and mountain areas, Wofford said.

The Los Angeles Department of Water and Power is fully staffing its electric trouble crews to respond to possible power outages. Mayor Karen Bass said the city is preparing resources to help residents stay cool.

“We are making sure cooling centers are available citywide, and are ensuring our most vulnerable neighborhoods have safe places to avoid the heat," Bass said in a statement Sunday.

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This story originally appeared in Los Angeles Times.