Santa Rosa's high of 106 degrees on Tuesday shattered a 79-year-old record, not that anyone who spent more than a few minutes outside needed convincing of that.
The hottest Sonoma County city, however, was Windsor, where a high of 109 left construction worker Brian Sheets withering in the sun, his faced streaked with sweat.
“Water, water, water,” Sheets said, as he refilled a bottle in an air-conditioned mobile office at the Old Redwood Highway site before heading outside again.
Across the Bay Area, high temperatures eclipsed or came close to eclipsing long-standing records.
San Francisco's high of 98 torched the previous record of 89 and tied the highest temperature ever recorded for the month of August, according to the National Weather Service.
Napa and Kentfield in Marin County both hit 105, breaking records set in 1931. San Rafael's high of 100 also broke a record set in 1971.
Santa Rosa's high easily topped the city's previous record of 102 set in 1931, a year when more than one-third of the summer baked in 90 degree or higher temperatures.
The summer blast will be shortlived. After another hot one predicted for today, temperatures will begin to fall rapidly on Thursday and will reach only the high 70s this weekend.
“It's going to be a dramatic cool-down,” said Duane Dykema, a Weather Service forecaster.
That will be welcome news for North Bay residents who had to curtail their outdoor activities Tuesday because of the heat.
In the Sonoma Valley, where the mercury reached 104 degrees, Glen Ellen resident Sam Avery and his Labradoodle, Buddy, had to wrap up their play time early at a dog park because of the intense afternoon heat.
“He's not moving too much,” said Avery.
At the Windsor construction site, work was being done on the roof, adding another 20-30 degrees to the ground temperature, said John Williams, field superintendent for the 64-unit Burbank Housing project.