Brutal Southern California Heat Wave Persists, Monsoonal Moisture Brings Chance of Thunderstorms

Coastal and valley areas are unlikely to see significant cooling until Monday or TuesdayPhoto byNWS

Southern California is experiencing a significant heatwave, with temperatures soaring 15 to 20 degrees above normal across inland coastal areas and valleys. On Thursday, the city of Indio hit 121 degrees, breaking its daily temperature record. Other areas in the Inland Empire and deserts also faced temperatures exceeding 100 degrees, even after sunset.

The heat is expected to continue into Friday, with only slight relief in the form of increased monsoonal moisture over the weekend. However, while this may limit extreme heating in the mountains and deserts, it will also bring higher humidity, providing little respite from the heat.

The National Weather Service has updated its forecast to include the possibility of showers and thunderstorms across inland valleys on Saturday and Sunday afternoons, particularly in the Elsinore Convergence Zone in the Inland Empire. While these storms may bring some rain, they pose a greater risk of strong winds and lightning due to the dry conditions in the lower atmosphere.

Coastal and valley areas are unlikely to see significant cooling until Monday or Tuesday, when drier weather is expected to return, gradually reducing the intensity of the heatwave.