People swin in an outdoor pool.
People swim at Cal Poly Maritime Academy in Vallejo on May 23, 2026. (Photo by Annie Barker/Stocktonia/CatchLight Local/Report for America)

Get ready for blistering heat across Stockton by the end of this week.

Starting Wednesday afternoon, a scorching heat wave will push temperatures into the high 90s, according to forecasts from the National Weather Service in Sacramento. By Thursday, highs are expected to blow past 100 — the area’s first triple digits of the year.

It’s “a pretty rapid warmup,” NWS meteorologist Katrina Hand said, noting that it’s unseasonable for this type of weather during this time of year in San Joaquin County and across Northern California. 

While June temperatures typically range in the low to mid-90s, Hand said extreme heat has been arriving earlier in the region. Last May, Stockton recorded a 106-degree day during a late spring heat wave.

The hot weather, coupled with gusty winds, could also increase fire risk along the northern edges of the county and across the Sacramento Valley, she warned. A red flag warning is in effect from 11 a.m. Wednesday through 5 p.m. Thursday for a wide swath of Northern California, although Stockton is currently not included in the danger zone.

“Heat is definitely a concern,” said Hand, noting that meteorologists will be tracking the trend through at least Saturday. “We encourage people to pay attention to the forecast and make sure they have a way to stay cool.” 

Earlier this week, a passing trough brought breezy conditions and cloud cover to the area. But a high pressure system that began building Tuesday is now driving the blistering temperatures, Hand said.

Heat will persist throughout the day, but evening Delta breeze could bring some minor relief, with temperatures dipping into the low 60s.

To beat the heat, Stockton has designated community centers and libraries as cooling zones. Some, like the Margaret Troke Library, the Stribley Community Center and the Fair Oaks Library, are open until 8 p.m. Thursday. All locations are closed Sunday. 

City officials could not confirm whether any cooling sites will extend hours during the heat wave.

A full list of county cooling centers, put together by its Office of Emergency Services, can be found here

City pools — including those at McKinley, Brooking and Holiday parks — are open until 6 p.m., except on Mondays. Free splash pads are also open 11 a.m.-7 p.m. daily.