San Francisco weather: Is this a Bay Area heat wave? Kind of

You're sweating just sitting in your stuffy house, and you're packing your family to head to the water park.

The Bay Area is experiencing its first real sweltering summer weather this week and you're wondering when this heat wave is going to die down.

But is it really a heat wave? 

"Well, it is, and it isn't," National Weather Service meteorologist Brayden Murdock told KTVU on Wednesday.

According to the NWS, a heat wave is "multiple" days – that's more than two – of "excessive temps." 

There is no set number for what an excessive temperature is, Murdock said, but it's anything that is 15 to 20 degrees above normal for that area – and remains that way, even overnight.

For example, if San Francisco is usually in the 60s and it's in the 80s, then that would count as "excessive." 

So, on the one hand, the Bay Area is seeing multiple days of hot weather: The excessive heat warning is expected to last from Tuesday to Thursday. 

On Tuesday, for example, Napa hit 101 degrees, Brentwood and Santa Rosa hit 100 degrees, and Sonoma and Concord hit 99 degrees.


National Weather Service adds beach hazard statement to heat advisory

Along with hot weather this week, the Bay Area also has dangerous beach conditions.

Murdock said there will be more of the same on Wednesday. 

There will even be some high peaks in eastern Contra Costa County that might reach 105 degrees. 

But, Murdock explained, this isn't a strong heat wave because the Bay Area is cooling off at night, with temperatures dropping into the 50s. 

"We're getting pretty good breaks from the heat overnight," he said.

The last full Bay Area heat wave was Labor Day 2023, Murdock said, where temperatures remained in the 70s and 80s overnight.

"I'm kind of on the fence about whether this is a heat wave or not," Murdock said.

That said, Murdock said this is indeed the first real hot weather system moving in over the Bay Area of the season and "people will really be feeling it."

"It's at least a small heat wave," Murdock said. "It's not something we can brush off."