The seasonal pools are closed. Many playground fountains have been turned off. Along Southern California’s beaches, some lifeguard towers are no longer staffed.
Summer is over.
But extreme heat is not. Forecasters say a dangerous heat wave is descending across much of Southern California, which is likely to bring triple-digit temperatures that will last at least a week.
Hot weather is not unusual in Southern California in October, but typically it lasts two or three days. The extended stretch of extreme heat makes this episode particularly dangerous, experts say.
October also tends to be one of the months when the risk of wildfires in Southern California is high because the vegetation has dried out after the summer and winds can grow stronger.
The wildfire risk will be elevated, particularly in inland valleys and mountains, but it is not expected to be so extreme as to prompt red-flag warnings.
Extreme heat warnings have been issued from Santa Barbara to San Diego, lasting through at least next Friday. Temperatures in downtown Los Angeles could reach 100 or higher on Saturday and Sunday, according to the National Weather Service. A few miles from downtown, the Dodgers are set to open a playoff series on Saturday in the middle of the day.
Temperatures will be even more extreme across the region’s inland valleys and deserts. Over the weekend, Death Valley National Park could reach 109 degrees, forecaster predict.
While the highest temperatures are likely to be recorded over the weekend, the weather next week is could feel equally stifling.
“We’re not going to see a pronounced peak in temperatures this weekend. It’s pretty much going to be hot through the entire week,” said Devin Black, a meteorologist with the Weather Service office in Oxnard, Calif.
Across the region, counties and cities were making preparations.
Officials were urging the public not to leave pets and children in vehicles. Crews were on alert for power outages. The Los Angeles County Fire Department has increased staffing and positioned units in some of the most high-risk places, said Jonathan Torres, a spokesman for the department.
County health officials also urged residents to stay hydrated and avoid going outdoors during the hottest hours. Those without air-conditioning, officials said, should take cool showers or baths, avoid using stoves and ovens, and seek shelter in a library, cooling center or mall.
Daniela Simunovic, the chief heat officer for the City of Los Angeles, said those at greatest risk were children, seniors and pregnant people, as well as people living in homes without air-conditioning or cooling. “This week is particularly dangerous,” she said.
Mr. Torres said high-risk heat conditions have become the norm.
“It used to be a season; now it’s year-round,” Mr. Torres said. “That’s just the reality that we have to live with here in Southern California.”
The expected heat wave is the first since the region suffered through scorching temperatures for two days in September, during which the temperature in downtown Los Angeles soared to 105, the highest recorded there so far this year.
Rose Schoenfeld, a meteorologist with the National Weather Service office in Oxnard, warned that heat events lasting six or seven days — and including high temperatures at night — could overwhelm the body’s natural cooling system, since there is no time for recovery.
Above normal temperatures in the Pacific Ocean have fueled tropical storms that have sent big waves to the Southern California coast. The increased storm activity is in part driven by the weather pattern known as El Niño that is particularly powerful this year and expected to affect winter weather around the globe. But Ms. Schoenfeld said she and her colleagues are not aware of a direct correlation between the coming heat wave and El Niño.
The heat will be accompanied by the winds that blow dry, warm air from inland areas toward the coast, while simultaneously, the sea breeze that pushes cool air off the ocean toward the coast will weaken, she said.
“That wind pattern is critical to what our temperatures will end up being,” said Ms. Schoenfeld.
While Southern California was wrapped in hot, sticky air much of the summer, relative humidity levels during this event are not expected to be high. The offshore winds pulling in dry air will help prevent muggy weather, but a hurricane churning far offshore could send moisture to the region as early as Saturday.
“It could be a little muggy, but not like it was during a lot of the summer,” said Ms. Schoenfeld.
The hurricane could also cause high surf and rip currents. In a social media post, the Weather Service warned beachgoers seeking relief from the heat not to go into dangerous waters.
Lifeguards in Los Angeles County said last month that over the summer they rescued more than 10,000 people from the ocean.
The post Extreme Heat in Los Angeles Area Expected to Last at Least a Week appeared first on New York Times.
