Dangerous heat dome to bring triple-digit temperatures to California, Southwest into next week
A prolonged heat dome will settle over the Southwestern United States late this week and persist into the weekend and next week, driving triple-digit temperatures from Southern California to the Desert Southwest and elevating wildfire risk. Temperatures will surge into the upper 90s to around 120 degrees in hot spots like Palm Springs and the LA basin’s interior valleys, with Las Vegas and Phoenix reaching 110–120 degrees. The extreme heat is reinforced by unusually warm air aloft and a slight offshore flow that channels heat toward coastal California. The combination of intense sun, minimal cooling at night, and gusty winds will amplify health risks and complicate outdoor activities, while storm chances remain limited to higher terrain. Outlooks point to winds increasing from a Pacific Northwest storm system and ongoing suppression of monsoonal activity, signaling a continued but potentially shifting heat threat into the following days.
Dive Deeper:
The heat dome is a long-duration high-pressure system predicted to settle over the Southwest late this week and linger through the weekend into the next week, with the center near the Arizona–Utah border. This configuration expands extreme heat across Southern California and the interior valleys.
Forecast high temperatures include mid-to-upper 90s in much of Southern California, while inland areas approach 100+ degrees; Palm Springs could near 120 degrees, illustrating the intensity of the heat.
A slight offshore breeze from the interior Southwest toward the Pacific Coast will help transport heat to the Los Angeles Basin, San Diego, and other southern California beaches, intensifying conditions near the coast.
Temperatures aloft are forecast to be unusually warm near the jet stream, contributing to exceptionally hot surface conditions across the deserts and Southern California.
Desert Southwest highs are expected to reach 110–120 degrees, with some locations challenging daily record highs, and the heat dome is expected to suppress much of monsoonal thunderstorm activity.
As the heat strengthens, a Pacific Northwest storm system is anticipated to bring stronger winds to parts of the West, adding to the overall risk environment and potential fire spread.
Fire risk is elevated due to the combination of extreme heat, abundant sunshine, and gusty winds, with any new fire likely to spread rapidly under these conditions.