Southern California is experiencing a late-season heatwave, with temperatures expected to hover around 100°F in downtown Los Angeles and even higher inland. The National Weather Service (NWS) has issued long-duration heatwave advisories, anticipating that these unseasonably high temperatures will persist for at least a week. Richard Bann, a meteorologist with the NWS’s Weather Prediction Center, stated, "We’re expecting temperatures will run some 15-20 degrees above normal – that’s pretty significant. Stay cool. Stay hydrated. Limit exposure to the sun."
Heatwaves in October are not uncommon for the region, often caused by ridges of high air pressure. This year, the situation is exacerbated by an ongoing marine heatwave and a strong El Niño, which is characterized by above-average surface-water temperatures in the Pacific Ocean.
Experts have noted that the severity and duration of this fall's heatwave are extreme, with V Kelly Turner, a professor of geography and urban planning at UCLA, commenting, "The extremely hot temperature Friday is rare, nearly 7°F hotter than the hottest October 2 ever and about 30 degrees higher than historical averages around 75°F."
Current forecasts do not predict strong winds that could exacerbate wildfire conditions, although the increased heat and low soil moisture still elevate the risk of wildfires. David Neelin, an atmospheric physicist at UCLA, explained that while it is challenging to attribute specific events to climate change, research indicates that every half-degree of global warming increases the likelihood and duration of heatwaves.
Neelin stated, "Overall, it’s hard to escape that a warmer climate adds to the strength of heatwaves. It adds to the probability of heatwaves and the likelihood of getting longer-duration heatwaves."
The heatwave coincides with major outdoor events, including the first game of the National League division series between the LA Dodgers and the Atlanta Braves. Edith de Guzman, a researcher at UCLA, emphasized the need for political investment in heat adaptation strategies to enhance livability in the region. She noted that providing more shade is the "most effective way to keep people safe" and warned, "Climate change is making longer-duration heatwaves possible, while simultaneously increasing their frequency and intensity."