Bay Area expected to heat up this week, with hottest temperatures in the South Bay

The Bay Area may feel more like summer this week, with temperatures expected to reach up to 90 degrees in some South Bay cities before cooling off next weekend, according to the National Weather Service.

A high pressure system will begin to build across the state starting Sunday, bringing warm, dry airs. Temperatures will peak on Thursday and begin to drop off over the coming weekend.

“People will probably notice a tangible jump in temperatures beginning with Monday,” said Drew Peterson, a meteorologist for the National Weather Service in Monterey. Santa Clara Valley is expected to be the hottest area.

Temperatures will climb seven degrees from Sunday to Monday in San Jose, to 81 degrees, and are expected to reach 86 degrees by Thursday. In Gilroy, temperatures will rise from 84 degrees on Monday to 90 degrees on Thursday, according to the National Weather Service forecast.

The high-pressure system will cluster around the South Bay and North Bay, said Peterson, with the possibility of high fire danger in parts of the North Bay starting on Wednesday night and into Thursday, because of low humidity and offshore winds that will increase later in the week.

“We’re considering a red flag warning for Wednesday night and Thursday, and potentially another one by late week, for higher terrain” areas, Peterson said.

Temperatures in North Bay cities will reach the low- to mid- 80s by Thursday; San Francisco is expected to be 75 degrees on Monday and reach 81 degrees by Thursday, while Walnut Creek will hit 86 degrees by Tuesday and stay that hot into Thursday.

East Bay temperatures will reach the low- to mid- 80s by Thursday: 82 in Oakland, 83 in Livermore and 84 degrees in Fremont.