LOS ANGELES, CA — A prolonged heat wave will send temperatures soaring across Southern California this week, bringing triple-digit highs, unusually warm nights and dangerous conditions that could persist into early next week.
A strengthening ridge of high pressure will expand west across the Southwest, pushing temperatures 5 to 10 degrees above normal in many communities beginning Wednesday, according to the National Weather Service.
Thursday through Sunday will generally be the hottest period, forecasters said. The combination of hot afternoons and elevated overnight temperatures will leave residents with little opportunity to recover from the heat.
Heat advisories will take effect at 10 a.m. Wednesday and remain in place through 8 p.m. Monday for downtown Los Angeles and the county’s inland coast, the San Fernando, San Gabriel and Santa Clarita valleys, inland Orange County, the San Diego County valleys and much of the Inland Empire.
An extreme heat warning will cover the Coachella Valley, the San Diego County deserts and the San Gorgonio Pass near Banning from 10 a.m. Wednesday through 8 p.m. Monday.
In LA County, highs of around 100 degrees will be common in the valleys and mountains. The western San Fernando Valley could reach about 106 degrees, while lower mountain elevations and far inland areas could climb as high as 107, forecasters said.
Downtown Los Angeles and other communities along the county’s inland coastal plain are expected to reach the upper 80s to mid-90s. Beaches will remain cooler, although the marine layer is expected to be shallow and largely confined to the immediate coast.
Inland Orange County and the San Diego County valleys will generally see highs ranging from the mid-80s through the mid-90s, with the warmest areas approaching 100 degrees. Overnight lows are forecast to remain in the mid-60s to lower 70s.
— NWS San Diego (@NWSSanDiego) July 21, 2026
The Inland Empire could see highs ranging from the upper 90s to 108 degrees. Riverside is expected to reach about 100 to 102 degrees each day from Wednesday through the weekend, while the Temecula Valley will climb into the mid-90s and possibly the upper 90s by Saturday and Sunday.
The most severe heat is expected in the Coachella Valley, where temperatures of 112 to 117 degrees are forecast. Overnight lows may remain in the mid-80s to mid-90s, sharply limiting nighttime relief.
Those planning a beach day to escape the heat should be aware that tropical systems in the Pacific Ocean could have a dangerous impact on SoCal's beaches.
South-facing beaches can expect peak surf of four to eight feet. Strong rip currents and high surf are expected all week, with a likely peak on Thursday and Friday, the NWS said.
High surf advisories are in effect for much of LA, Orange and San Diego counties.
A limited amount of monsoonal moisture may reach the mountains and deserts Thursday and Friday.
Forecasters placed the chance of showers at about 15% to 20%, with only a 5% chance of thunderstorms developing. Dry weather is expected to return over the weekend and continue into early next week.
"There is a high risk for dangerous heat illness, especially for sensitive groups like the very young, the very old, those without air conditioning, and those active outdoors," forecasters said.
Officials urged residents to ensure they drink plenty of fluids, seek relief in air conditioning, stay out of the sun and check up on relatives and neighbors.
Strenuous activities should be limited to the early morning or evening, officials said.
City News Service contributed to this report.
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