By Reginald Stanley. Posted May 10, 2025, 8:39 PM.

A strong upper-level ridge brought dangerously hot conditions to much of Southern California late this week, with high temperatures peaking near or just above 100 degrees across the inland valleys Saturday afternoon.

The National Weather Service issued a Heat Advisory for the inland valleys, set to end at 9 PM Saturday evening. The hottest temperatures of the year so far occurred Saturday across the region, with five WeatherCurrents stations reaching or exceeding 100 degrees. Afternoon temperatures on Saturday were up to 25 degrees above average for this time of the year. WeatherCurrents' station in Lake Elsinore recorded the hottest temperature Saturday afternoon, peaking at 105 degrees - breaking the previous record high for May 10 at that location, which was 97 degrees in 2006. Triple-digit highs were reached in Temecula, Murrieta, French Valley, and Moreno Valley. High temperatures in Riverside, Fallbrook, and East Hemet all measured in the upper 90s. Anza was the mildest location in the WeatherCurrents network, with a high of 89 degrees Saturday afternoon.

An approaching low pressure system early next week will rapidly cool the region off starting Monday and Tuesday, which will also usher in the return of the marine layer. Patchy drizzle may develop, particularly along the coastal mountain slopes.