A sweeping heat advisory covering more than five million residents across six Southern California counties took effect Thursday morning, as an anomalous early-season heat event pushes temperatures into territory rarely seen before summer. The National Weather Service is urging vulnerable residents to stay indoors as forecasters warn the 34-hour advisory could give way to even more extreme conditions extending well into next week.
The advisory spans San Diego, Orange, Riverside, San Bernardino, Los Angeles, and Ventura counties, with the warning window running from 10 a.m. Thursday through 8 p.m. Friday. Officials cautioned that relief will not arrive promptly after the advisory expires, elevated temperatures are expected to linger through the weekend and beyond, with the NWS Climate Prediction Center’s outlooks anticipating above-average readings across California and the broader U.S. West through at least March 24.
Records Under Threat as Temperatures Soar Weeks Ahead of Schedule
The scale of this event has caught even experienced meteorologists off guard. According to NWS meteorologist Sebastian Westerink, “This is very anomalous heat for the month of March. We typically don’t see upper 90s or 100s until June.” The average high for the region at this time of year sits at just 73 degrees, making the projected readings some 25 to 30 degrees above the seasonal norm.
Several records are at risk of falling. In San Diego, Orange County, and the Inland Empire, temperatures are forecast to climb between 93 and 98 degrees in inland zones, with upper 80s to lower 90s expected along the coast. The Los Angeles and Ventura county forecast is similarly stark, with widespread readings of 90 to 100 degrees anticipated.
WFLA-TV chief meteorologist Jeff Berardelli noted on X that Downtown Los Angeles could hit 100°F on Friday, a figure that would shatter the city’s all-time March record of 97 degrees and arrive three full weeks ahead of the earliest-ever 100-degree reading in the city’s historical record, which occurred on April 4th.
Vulnerable Populations Face Elevated Health Risks
Health officials and forecasters are placing particular emphasis on the dangers facing residents without reliable access to air conditioning, as well as those who work or exercise outdoors. According to the Los Angeles/Oxnard NWS office, there is a “high risk for heat illness” across the region, and additional advisories, or potentially more severe extreme heat warnings, may be issued if conditions deteriorate further in the days ahead.
Young children, older adults, and outdoor workers are considered most at risk for heat exhaustion or heat stroke. Residents have been urged to drink plenty of water, limit strenuous activity to early morning or evening hours, wear lightweight and loose-fitting clothing, and check in on elderly neighbors and family members.
The heat event stands in sharp contrast to conditions developing elsewhere in the country. Arctic air is expected to descend into the Midwest early next week, dropping temperatures there by as much as 40 degrees from current levels, a dramatic illustration of the competing weather extremes gripping the nation simultaneously.
