End of summer? Bay Area heat didn’t get the message

Bay Area residents returned to work after the Labor Day holiday with temperatures in triple-digits in the hottest spots in the Bay Areas and in the 90s most everywhere else.

The menu is about the same for Wednesday and again for Thursday, according to the National Weather Service.

So much for the unofficial end of summer.

“We are going to see a lot of this intense heat through Thursday,” meteorologist Dial Hoang said. “There is high pressure over the Western United States, and that’s allowing this hot weather here to build.”

The heat wave is the longest and most intense since 100-degree temperatures regularly dotted the map in July. Hoang said this one will be relatively short, as a high-level trough is expected to drop in from the Gulf of Alaska and drop temperatures significantly Friday.

Until then, the region will bake. A heat advisory was set to go into effect beginning at 11 a.m. Wednesday morning and was scheduled to remain in place until 11 p.m. Thursday. The advisory covers the East Bay Interior Valleys and Hills, the North Bay Interior Mountains, the Eastern Santa Clara Hills, the Santa Cruz Mountains, the Santa Lucia Mountains and the San Benito Mountains.

Temperatures in the hottest spots Wednesday were expected to climb to 103 degrees in Brentwood and 101 in Livermore. Concord also was expected to climb to 101, while Pleasanton was expected to reach 99. San Jose was likely to peak at 97.

Those temperatures were expected to rise by a degree or two on Thursday, according to the weather service. Cooling centers were expected to be open in Alameda, Contra Costa and Santa Clara counties.

On Tuesday, Concord reached 101, Livermore 99 and San Jose 93, according to the weather service.

The high pressure also is expected to trap pollution closer to the surface, and a Spare the Air Alert remained in place for the second straight day. The Bay Area Air Quality Management District has issued six of those in 2024.

Relief from the heat is expected Friday, when temperatures are expected to drop 5-7 degrees. Hoang says that as the lower pressure gains a firmer hold Saturday, temperatures are expected to return to their seasonal averages, and temperatures are not expected to surpass 90 degrees.