As March unfolds, the American Southwest and California are experiencing a heatwave that’s nothing short of historic. The region, more accustomed to mild spring temperatures, has been thrust into a relentless, summerlike blast that’s shattering records and testing the resilience of millions. According to The Weather Channel, a long-lived, historic March heat wave is underway, bringing with it unprecedented temperatures and a host of public safety concerns.
Southern California, in particular, is at the epicenter. On March 16, 2026, the mercury at Hollywood Burbank Airport soared to 92 degrees, breaking the previous daily record set in 2004. Pierce College in Woodland Hills saw an even more dramatic spike, hitting 97 degrees—three degrees higher than the 2007 record. Yet, as meteorologist Robbie Monroe of the National Weather Service in Oxnard noted, "it’s just the beginning." Monroe explained that, due to offshore winds pushing warm, dry air from the mountains and deserts toward the coast, temperatures would climb even higher. "We’ll probably add another five to seven degrees of warming today," Monroe said on Tuesday. "But some of the coastal areas will see 10 to 20, maybe even 25 degrees, of warming compared to yesterday."
The numbers have been nothing short of staggering. By March 17, downtown Los Angeles recorded a high of 98 degrees, toppling a record that had stood since 1914, according to the National Weather Service. Burbank Airport reached 99 degrees, not only breaking the previous March 17 record but also setting a new all-time high for the month. Anaheim and Santa Ana each peaked at 100 degrees, shattering records set in 2010 and 1978, respectively. Riverside didn’t escape the onslaught either, reaching 101 degrees and obliterating its previous record by nine degrees. Meteorologist Philip Gonsalves of the NWS remarked, "More than likely there will be more records set or tied."
But it’s not just about the numbers. The timing of this heatwave is what makes it so dangerous. Typically, Southern California sees March temperatures in the high 60s or 70s. This year, however, the region is enduring temperatures 15 to 30 degrees above average. The National Weather Service’s Extreme Heat Warning—affecting more than 18 million people across Southern California, southern Nevada, and parts of Arizona—remains in effect through the evening of March 20. Millions more are under heat advisories, with forecasters warning that highs will stay in the upper 90s in Los Angeles and low 90s in Orange County, while the Inland Empire can expect highs around 100 degrees in Riverside and 101 in San Bernardino.
The impact is widespread. The heat dome, as described by AccuWeather meteorologist Elizabeth Danco, is expanding across several states, potentially affecting up to 70 million people through the weekend and possibly into early next week. Danco warned, "The impacts of this heat will extend beyond daily temperature records, with faster snowmelt, drying vegetation and growing stress on water resources across parts of the West." These conditions could accelerate the onset of wildfire season, a concern echoed by Cal Fire Battalion Chief Brent Pascua, who noted that while vegetation still has some moisture, authorities are vigilant due to the current lack of rainfall and fast-drying conditions.
For many, the heatwave is more than just an inconvenience—it’s a serious threat to health. According to a Los Angeles Times analysis, heat is the leading cause of weather-related deaths in the United States, resulting in hundreds of fatalities each year. Since 1999, heat has caused or contributed to the deaths of more than 21,500 Americans. The National Weather Service cautioned, "There is a high risk for dangerous heat illness for anyone, especially the very young, the very old, those without air conditioning, and those active outdoors." Warm overnight temperatures are compounding the risk, offering little relief and putting additional strain on vulnerable populations, particularly in mountain and foothill communities.
Communities are being urged to take precautions. The Environmental Health and Safety office at UC Irvine recommends drinking 3 to 4 cups of water every hour, taking frequent breaks in shaded or cool areas, and avoiding alcohol and caffeine, which can dehydrate the body. If symptoms such as nausea, dizziness, weakness, or unusual fatigue occur, individuals are advised to rest in a cool, shaded area and seek medical attention if symptoms persist. Wearing lightweight, protective clothing and keeping an eye on at-risk neighbors and loved ones are also key steps. Public libraries and community centers are serving as cooling centers, providing refuge for those without access to air conditioning. Information about local cooling centers is available for Los Angeles, Orange, Riverside, and San Bernardino counties.
The list of affected locations is extensive, spanning Santa Clarita Valley, downtown Los Angeles, the Santa Monica Mountains, Calabasas, San Fernando Valley, and reaching as far as the Santa Ynez Mountains and Ojai Valley. The heat advisory issued by the National Weather Service on March 17, effective from 9:12 a.m. until 10 a.m., warned of "dangerously hot conditions with temperatures between 96 and 104 degrees expected." The warm overnight lows are expected to contribute to the heat risk, particularly in mountain and foothill locations.
Looking ahead, the forecast offers only modest relief. While next week is expected to be cooler, temperatures are still predicted to remain 10 to 15 degrees above normal. The heatwave is likely to challenge or even break monthly records, with Los Angeles potentially surpassing its March record of 99 degrees. If the heatwave persists for five days, it will mark the longest such event recorded this early in the year, surpassing the previous record set in March 2015.
Other major cities in the Southwest are feeling the heat as well. Phoenix could reach up to 106 degrees between March 19 and 21, about 20 to 30 degrees above its historical average. In Phoenix, the earliest recorded 100-degree day was March 26, 1988, but typically, such temperatures don’t arrive until May. Las Vegas could also hit 100 degrees, weeks ahead of its usual timing for triple digits. Even Northern California is experiencing record heat, with Redwood City breaking its March record and San Francisco expected to see highs in the lower 80s.
Climate scientist Daniel Swain summed up the situation succinctly on X: "It’s a full-on summer heat wave in March." The early-season heat is particularly dangerous because communities haven’t had time to acclimate, making heat-related illness more likely. The National Weather Service is urging everyone to take the threat seriously, emphasizing the importance of hydration, seeking shade, and looking out for those most at risk.
As the Southwest bakes under this historic March heatwave, the message from meteorologists and health officials is clear: stay cool, stay safe, and be prepared for the unexpected. With records falling and the summer still months away, the region is facing a stark reminder of the growing challenges posed by extreme weather.