At least 37 million residents across California are under heat alerts on Sunday as a dangerous, multi-day October heat wave continues to bake the state. Temperatures are forecasted to climb 20 degrees above seasonal norms, pushing readings into the 90s and triple digits from the San Francisco Bay Area down to the Mexican border.
In urban centers, warm nighttime temperatures are expected to offer minimal relief from the daytime heat. As of October 4, 2026, excessive heat warnings and heat advisories have been issued for nearly the entirety of the state. Southern California remains under an excessive heat warning through Thursday at 8 p.m. local time, with Los Angeles, Riverside, and Temecula anticipating highs in the triple digits, while San Diego is expected to reach the upper 90s.
The extreme conditions have already led to record-breaking temperatures. On Saturday, at least eight cities in Southern California broke daily high-temperature marks. Anaheim and San Diego both hit 105 degrees, and Santa Ana reached 107 degrees. Additionally, Vista, located north of San Diego, recorded a high of 108 degrees, breaking a daily record and tying an all-time record set on June 30, 1985.
Forecasters expect the hot weather to shift eastward across the Great Basin over the coming days, with temperatures there expected to remain in the 80s and near 90s.
Meanwhile, the Gulf Coast and Southeastern United States are bracing for unsettled weather. A flood watch is in effect on Sunday stretching from Louisiana through Florida and Georgia. A level 2 risk for excessive rainfall and flash flooding has been designated from New Orleans into the Carolinas, while the lower Texas coast faces a level 3 “significant” risk.
The heaviest precipitation is predicted along the Gulf Coast and Florida Panhandle, with rainfall totals of 2 to 6 inches expected. Localized areas could see 8 to 10 inches, particularly between Mobile, Alabama; Biloxi, Mississippi; and Pensacola and Panama City, Florida. Rainfall rates of 1 to 2 inches per hour are possible along the Texas coast.
Don’t forget the flood risk in the Southeast! It’s wild how one storm system can cause such opposite weather extremes.
Meanwhile my AC bill is going to kill me. Why does it have to be this hot right when fall should start?
Isn’t this just climate change accelerating? It feels like we’re entering a new normal every single year now.
We really need better urban planning for these extreme heat events. The concrete jungle offers zero relief at night.
108 in Vista? That’s absolutely insane for October. Stay safe everyone and drink lots of water!