A three-digit heat wave is set to southern California through the end of the week, with near-record high temperatures across the state.
The National Weather Service warns of dangerously hot conditions, including temperatures as high as 106 degrees in Sacramento on Friday and 117 degrees in Borrego Springs on Saturday.
In the Los Angeles area, the Antelope Valley could soar to 105 degrees by Saturday, a potential record. Several warnings about excessive heat and heat advice have been issued in the state.
“We’ve had some previous heat waves this year, but not as intense as this or that long duration,” weather service meteorologist Alex Tardy said in a briefing about the excessive heat.
The heat wave could also worsen air quality and increase the risk of a wildfire spreading if a flame were to ignite, officials said.
The South Coast Air Quality Management District has issued one heat wave ozone advice for Los Angeles, Orange, Riverside and San Bernardino counties through Sunday, where high smog levels are expected as temperatures rise.
“Elevated temperatures, which increase the rate of ozone formation and increase emissions of chemicals leading to ozone formation, combined with predicted light winds, can cause unusually high and persistent levels of ozone pollution,” the agency said.
Smog levels are likely to lead to unhealthy air conditions in parts of the South Coast Air Basin and Coachella Valley, they said.
In Los Angeles, temperatures will be much higher in the interior than on the coast, according to David Sweet, a meteorologist at the Oxnard Weather Service.
“There’s a really, really big difference between the temperatures on the coast, which will be just a few degrees above normal, and the temperatures over the Antelope Valley, which will be close to records,” he said.
Temperatures in Palmdale and Lancaster on Friday could surpass their previous records for the date, 103 degrees for both, set in 1985, Sweet said.
Extreme heat is one of the most deadly consequences of climate change, experts have said, and heat waves are increasing in frequency and duration. A Times study last year found that heat deaths are chronically underestimated in California and can be as much as six times higher than previously thought.
Last summer, a record-breaking heat wave in the northwestern Pacific in late June killed dozens of people as well as an estimated 1 billion marine animals along the coast.
Forecasters this week are advise residents To stay hydrated, seek shade and avoid strenuous outdoor activities. People should wear light, loose-fitting clothing and never leave children or pets alone in a car.
“During hot and humid weather, your body’s ability to cool itself is challenged in ways you might not expect,” the weather service said.
Signs of heat exhaustion and heat stroke include dizziness, thirst, nausea and weakness.
Heat waves in June last year also helped start this year’s fire season, with the Sugar fire and the Beckwourth Complex fire igniting not long after record temperatures baked vegetation across the state. The weather service advises residents be careful with sparks or fire.
Adam Roser, a meteorologist at the San Diego Weather Service, also noted that night temperatures will remain toasty during the heat wave, including nighttime lows in the 80s in Coachella and Palm Springs.
“The lowest night will be pretty hot,” Roser said. “So there is very little in the way of relief.”