SAN FRANCISCO (KRON) — A major warm-up is headed for the Bay Area this week, arriving right in time for the culmination of the annual San Francisco Fleet Week. Temperatures above 90 degrees are forecast across the Bay Area beginning on Thursday into Friday, according to the National Weather Service.

Even places along the coast are expected to feel the heat as the Bay Area’s “natural air conditioner” takes a couple days off.

“Temps will be heading into ‘San Francisco Summer,’ our fall warm-up this week,” said KRON4 Meteorologist Kyla Grogan.

When does the heat begin?

“The wind tonight is going to start rolling in the North Bay Hills with the gustiest time being overnight tonight into Wednesday morning. I’m looking out for some of those gusts to be 25 – 30 mph,” said Grogan. 

“The breezy offshore conditions are a result of the dynamic between a departing low-pressure system and a strengthening high-pressure system. As that high pressure that’s currently off the coast starts to dominate our weather pattern, we will see temperatures lift well above average,” she added.

How hot will it get?

According to the NWS, there is increasing potential for 90+ temps in the following areas:

  • North & East Bay Valleys
  • Santa Cruz Mountains
  • South Bay & Santa Clara Valley
  • Southern Salinas Valley

Even San Francisco is looking at temperatures well above average this week.

“Not only will some inland spots be in the mid 90s, but San Francisco is looking out for mid 80s and even the coast will likely see upper 70s and a few spots may even top out at 80 degrees,” said Grogan. “It doesn’t appear that we’ll be breaking any records, but we will definitely feel like we’re on a very summer-like swing through Saturday. 

Fleet Week weather

The good news is that this week’s warm-up is expected to bring clear skies and nice sunny weather that’s perfect for enjoying Fleet Week events.

“This does bode well for our Fleet Week festivities as the strengthening high pressure will bring lots of sunshine to San Francisco and will also help to compress our marine layer leading to quicker clearing of any marine layer stratus,” said Grogan.

Will the warm-up bring fire danger?

The downside of the high heat is that it could bring an increased chance of fires.

“So far, no critical fire weather and our fuels are not horribly dry, thankfully,” Grogan said. “But while no Red Flag Warning is issued, we do have elevated fire danger because of this push of offshore wind that thankfully is not extreme and should ramp down as we move into Wednesday afternoon.”

How long will the warm-up last?

“The warm-up is Wednesday through Saturday and then we roll it back and get our onshore breezes again next week,” Grogan said. “By Sunday our weather pattern will change and return to a more classic Bay Area set up so a return of onshore flow and marine layer influence as well as cooler temps end our weekend.”