An Extreme Heat Warning is currently in effect for a large portion of Southern California, issued by the National Weather Service Los Angeles/Oxnard CA, NWS San Diego CA, and NWS Hanford CA. The warning became active on Tuesday, July 29, 2026 at 1:17 PM PDT and runs through Sunday, August 2, 2026 at 8:00 PM PDT. Anyone in the affected zones should treat this alert as active and ongoing for the full duration of that window.
The areas covered under this warning are extensive. They include the Interstate 5 Corridor, the Western Antelope Valley Foothills, Cuyama Valley, Coachella Valley, San Bernardino and Riverside County Valleys (the Inland Empire), Apple and Lucerne Valleys, the Santa Ana Mountains and Foothills, San Diego County Inland Valleys, Riverside County Mountains, San Diego County Mountains, Orange County Inland, and the Indian Wells Valley. Residents and travelers moving through any of these zones between now and the evening of August 2 should plan accordingly.
What NWS Is Telling Residents to Do Right Now
The National Weather Service is direct in its guidance. Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check on relatives and neighbors. These are the first steps officials want every person in the affected areas to act on immediately.
One of the most urgent reminders in the alert concerns vehicles. Do not leave young children or pets in unattended cars. According to NWS, car interiors can reach lethal temperatures within minutes, even with windows cracked. This applies at any hour of the day during an active Extreme Heat Warning.
For anyone who must be outdoors, NWS instructs residents to wear lightweight, loose-fitting clothing and to limit strenuous physical activity to early morning or evening hours when temperatures are lower. Knowing the signs of heat exhaustion and heat stroke, and acting on them quickly, is essential. Heat stroke is a medical emergency: call 9-1-1.
For outdoor workers specifically, the alert references guidance from the Occupational Safety and Health Administration recommending frequent rest breaks in shaded or air-conditioned environments. Any worker overcome by heat should be moved immediately to a cool, shaded location while emergency services are contacted.
If you do not have air conditioning at home or lack access to shelter, call 2-1-1. That line can help connect you with appropriate cooling resources in your area. NWS also advises monitoring the latest forecasts and official warnings through the duration of this event, as conditions or coverage areas may be updated before the August 2 expiration.
Putting This Event in a Broader Preparedness Context
Extreme heat is one of the most underestimated weather hazards in the United States, but it consistently ranks among the deadliest. For households in Southern California and across the Southwest, the period of late July through early August represents a predictable window of elevated risk each year. Building a basic heat preparedness plan, knowing where your nearest cooling center is, keeping extra water on hand, and establishing a check-in routine with elderly neighbors or family members are all low-cost steps that make a measurable difference. The current warning covers densely populated valleys as well as mountain and rural zones where access to cooling resources may be limited, which makes community awareness especially important before the warning expires on the evening of August 2.
For the fundamentals that apply beyond this specific alert, see our Power Outage Preparedness guide.
Source: National Weather Service (NWS Los Angeles/Oxnard CA, NWS San Diego CA, NWS Hanford CA). Active alert data retrieved 2026-07-29 22:00 UTC via api.weather.gov.
