Exceptionally long heat wave hitting Southern California, could last until mid-October

Iris Kwok, Los Angeles Times on Oct 1, 2026

By clicking submit, I authorize Arcamax and its affiliates to: (1) use, sell, and share my information for marketing purposes, including cross-context behavioral advertising, as described in our Privacy Policy , (2) add to information that I provide with other information like interests inferred from web page views, or data lawfully obtained from data brokers, such as past purchase or location data, or publicly available data, (3) contact me or enable others to contact me by email or other means with offers for different types of goods and services, and (4) retain my information while I am engaging with marketing messages that I receive and for a reasonable amount of time thereafter. I understand I can opt out at any time through an email that I receive, or by clicking here

LOS ANGELES — Summer has ended, but in Southern California the extreme heat has not. On the heels of a miserably sticky summer, an unusually long October heat wave is set to arrive, according to forecasters.

"Dangerously hot conditions" are expected to descend Friday, when an extreme heat watch goes into effect for the L.A. County region, lasting through Oct. 8, with the possibility of being extended.

The heat wave could drag on through mid-October, according to forecasters.

Saturday is expected to be the peak of the heat wave, with temperatures reaching triple digits in parts of Los Angeles and Ventura counties, according to the National Weather Service. Downtown Los Angeles and Pasadena are forecast to reach 100 degrees, while Paso Robles could reach 101 degrees and Ojai 102 degrees.

The National Weather Service in San Diego also issued an extreme heat watch from Friday morning through Wednesday night for inland and coastal areas of Orange and San Diego counties, as well as parts of San Bernardino and Riverside counties.

"This is one of the longer-duration ones that I've seen in my time at this office," said National Weather Service Oxnard meteorologist Rose Schoenfeld, who joined the weather service in 2023.

Schoenfeld said the heat wave — which is being driven by high pressure in Southern California and a lack of wind — does not have a clear cutoff. Weather service models indicate it might last through the middle of the month, she said.

Southern California has had a particularly swampy summer, thanks to tropical storm remnants and unusually warm ocean temperatures.

Mosquitoes have been thriving amid the damp conditions, fueling the number of West Nile virus cases in Los Angeles County.

Fortunately, the weather service is expecting this heat event to be less humid than those this summer, Schoenfeld said.

However, a storm that is not expected to make landfall could send some moisture toward Southern California over the weekend and into Monday.

That could bring some elevated humidity and a small chance of thunderstorms and cloud coverage in mountainous areas, but not enough to significantly lower temperatures across the region.

"Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors," the weather service advises. "Do not leave young children and pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes."

October heat waves are normal in the Los Angeles region, where seasons are "a little asynchronous" with classic seasons, Schoenfeld said. The warm season typically lasts from June through October.