Southern California residents are preparing for a dangerous and prolonged heat wave starting Friday, with temperatures anticipated to reach triple digits in several areas. The National Weather Service (NWS) has issued an Extreme Heat Warning, which will be in effect from 10 a.m. Friday through 8 p.m. Thursday for both coastal and valley areas of Los Angeles County, as well as coastal and inland Orange County.
Friday is expected to bring temperatures 10 to 15 degrees above normal. Along the Los Angeles County coast, highs could range from the mid-to-upper 80s, with some parts hitting the lower to mid-90s. Valleys in Los Angeles County are forecast to see temperatures between the upper 90s and 105 degrees. In Orange County, coastal areas can expect mid-80s to around 90 degrees, potentially reaching the lower to mid-90s near higher coastal terrain. Inland Orange County will likely experience mid-90s to near 100 degrees.
The NWS stated that Friday marks the start of "the well advertised long duration heat wave." Forecasters anticipate Saturday will be the hottest day of the upcoming week, with temperatures rising an additional 2 to 4 degrees in coastal and valley areas, and potentially as much as 6 degrees locally. Most coastal areas are expected to reach the 90s on Saturday, while valley temperatures could soar to between 100 and 107 degrees, which is about 15 to 20 degrees above normal. The NWS reiterated that "This will make Saturday the hottest of the next 7" days.
While the heat is expected to ease only slightly on Sunday, temperatures will generally remain 10 to 15 degrees above normal through Wednesday. Overnight temperatures will offer limited relief, with lows in both coastal and inland Orange County remaining mostly in the lower to mid-70s. The National Weather Service emphasized that even if the heat wave doesn't break records, it will be "very dangerous due to the prolonged duration of the event," cautioning that the "relentless heat will have a hazardous wearing down effect on people," particularly the very young and old.
Adding to the conditions, humidity is expected to increase from Monday through Wednesday as moisture from Hurricane Rachel moves into the region. This could bring a 5% to 15% chance of afternoon showers or thunderstorms in the mountains. Long-range models suggest conditions might begin to improve around October 10.
In response to the severe forecast, local health and emergency officials have issued advisories. The Los Angeles County Department of Public Health urged residents to stay hydrated, avoid outdoor activity during the hottest hours when possible, and seek air-conditioned spaces or cooling centers if their homes cannot be kept cool. Dr. Muntu Davis, Los Angeles County Health Officer, highlighted that "Heat causes more deaths in the U.S. annually than floods, storms, and lightning combined," identifying older adults, young children, outdoor workers, athletes, and individuals with chronic medical conditions as those most susceptible to illness. He also advised seeking immediate medical help for symptoms of heat stroke or heat exhaustion, such as dizziness, nausea, rapid heartbeat, confusion, or passing out.
County health officials also recommended checking on high-risk individuals, including older adults, children, pregnant people, those with chronic health conditions, individuals who live alone, and outdoor workers. Residents without access to air conditioning can locate cooling centers, splash pads, and community pools by calling 211. The City of Los Angeles Emergency Management Department echoed these warnings, stating downtown Los Angeles could reach 100 degrees, the coast 90 degrees, and the valleys 105 degrees. City officials advised using public libraries, recreation facilities, senior centers, or other air-conditioned public buildings, suggesting residents call 311 or use the city’s Cool Spots LA online tool to find nearby cooling facilities. For those who must work, exercise, or spend extended periods outdoors, officials urged rescheduling strenuous activities for early morning or evening when possible, wearing lightweight and loose-fitting clothing, and taking frequent breaks in shaded or air-conditioned areas. Anyone experiencing possible heat stroke should be moved to a cool, shaded location and 911 should be called.
