After Weeks of Chill, the Bay Area Finally Gets Its Summer Sizzle

San Francisco’s Dolores Park is about to get lit.

It’s going to be the perfect weekend to ride a ferry to Sausalito, hike in the woods or have a picnic at your favorite outdoorsy spot. The Bay Area is set to have its first warm-up in weeks, and forecasters say the sunny weather will last through the weekend.

But with blue skies comes elevated wildfire risk, so experts are urging residents to stay alert and take precautions.

With a break from one of the coolest summers since 1999, forecasters said the warmest days this week will likely be Friday and Saturday, bringing possible triple-digit temperatures to North Bay cities from Santa Rosa to Cloverdale and East Bay cities like Concord and Livermore.

South Bay cities, like San José, could reach the lower 90s. San Francisco, which hit 75 on Wednesday, will remain in the high 60s.

“It’s going to be one of our more notable warm-ups this summer,” said Matt Mehle, a lead meteorologist with the weather service’s Bay Area office.

The weather service has categorized the risk associated with the warmer temperatures as moderate, meaning most people used to the heat should be able to handle the temperatures. Still, there is some health risk for those who are more sensitive, like seniors, infants and outdoor workers.

But this round of heat won’t last, Mehle said, with warmer weather beginning to cool off by next Tuesday.

Why the sudden change from gloomy weather to summertime sunshine?

Mehle said the marine layer has weakened, allowing temperatures to rise. A ridge of high pressure over the southwest is starting to suppress the fog that’s shrouded the region in grey. That ridge, which has caused temperatures to soar to 110 degrees in places like Arizona, is beginning “to squeeze over the Bay Area.”

The near triple-digit heat nearly encircling the Bay Area also increases the chance of wildfires igniting through early next week. Forecasters expect relative humidity to be low and for coastal winds to pick up, which could help spread sparks.

The weather service doesn’t plan, at this time, to issue a red flag warning, but Mehle said fire risk is near critical.

“You could probably see an uptick in some grass fires or starts in the Bay Area, but nothing that’s gonna transition to a large fire,” Mehle said.