L.A. County – A National Weather Service heat advisory for Los Angeles County and the Southland begins Tuesday and runs through Thursday, with interior valleys likely to hit 90 to 105 degrees. Forecasts show a brief cooldown after Thursday, but forecasters warn the heat may
By Tuesday morning. the air over Los Angeles County is expected to feel different—thicker. hotter. and especially punishing for people who live in valleys and away from the coast. The National Weather Service has issued a heat advisory for this week that includes Los Angeles County and other parts of the Southland. with temperatures climbing beginning Tuesday and lasting through Thursday.
In the Santa Clarita Valley. the east and west San Fernando Valley. parts of the San Gabriel Valley. and northwest L.A. County mountains, the forecast calls for the most severe heat. Temperatures are expected to reach 90 to 105 degrees in the interior. Along the inland coastal plain—including downtown Los Angeles—the mercury is projected to rise to 80 to 90 degrees. In the foothills and canyons of southwest Santa Barbara County. highs are expected to be in the 80s and lower 90s.
Rose Schoenfeld, a meteorologist with the National Weather Service in Oxnard, said the heat is running above seasonal norms. “Temperatures should be five to 10 degrees above normal for this time of year thanks to a high-pressure system building up over the region,” she said.
Forecasters expect temperatures to drop after Thursday, but the relief may be short-lived. Schoenfeld cautioned that even as highs ease, the region may not fully cool down. “Looking ahead. you might be seeing some outlooks that look pretty favorable. but that heat will linger and redevelop with a pretty impressive heat wave for much of the west. that would be starting next weekend or so. ” she said. “It doesn’t seem like we’re out of the woods, even if temperatures start to drop after Thursday.”.
The heat arrives as a broader marine pattern settles over the Pacific Ocean. The forecast discussion notes a major marine heat wave across the Pacific Ocean that has the potential to affect weather events around the world—bringing months of warmer oceans. Those warmer waters can contribute to thunderstorms and extreme heat thousands of miles away.
Record heat in other regions has already shown how disruptive extreme temperatures can be. In recent weeks, record heat waves have baked parts of Europe, with temperatures hitting 104 degrees in some countries. France has reported more than 1,000 heat-related deaths. In the United States. record heat has gripped much of the Midwest and East Coast. with temperatures between 110 and 115 degrees in major metropolitan areas. The National Weather Service issued an extreme heat warning for much of the Midwest, Mid-Atlantic and Northeast.
The fallout has reached beyond health—affecting travel and summer events. The sweltering temperatures have disrupted travel and led to cancellations planned for celebrations over the Fourth of July weekend. including Philadelphia’s Salute to Independence parade. The Great American State Fair on the National Mall in Washington was forced to shut down for a few hours. Amtrak canceled some trains in the Northeast because of excessive heat that could affect the tracks.
For Southern California residents. the message is straightforward: the hottest stretch is expected to come Tuesday through Thursday. with the most intense heat in interior valleys and mountain areas. After that, the forecast may offer a break—but forecasters are warning not to assume the worst is finished.
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