Slightly cooler North Bay temperatures Sunday don’t mean the heat is entirely over

Sunday brought cooler temperatures to many areas of the North Bay after days of scorching heat over the July 4 holiday weekend.

But with generally warm weather still on tap, slight shifts in the mercury may not be noticeable to everyone.

Anyone who endured Saturday’s record high of 117 degrees in Ukiah would be hard-pressed to feel relief in the 109-degree day that followed on Sunday.

And while the temperature dropped 15 degrees Sunday at the Charles M. Schulz-Sonoma County Airport ― from 101 Saturday to 86 degrees on Sunday ― it was still a pretty warm day, if a tad more comfortable.

“It’s a very slight downslope,” said Nicole Sarment, a meteorologist with the National Weather Service in Monterey. “Even then, we’ve had seven days of extreme heat. So just because it’s cooling off by 2 degrees doesn’t mean your body is going to feel it.”

An excessive heat warning and heat advisory are both to remain in effect through 11 p.m. Wednesday, with temperatures actually heading up above 90 degrees Wednesday and nearing 100 on Thursday in Santa Rosa.

The same is true for Napa. In Ukiah, the excessive heat warning expires at 8 p.m. Monday ― even though temperatures are forecast to remain above 100 for the rest of the week.

The 117-degree mark hit Saturday at the Ukiah Municipal Airport smashed the record high for that date of 108, set in 1905.

Across all dates, mercury had climbed to 117 only one other known time in Ukiah, on Sept. 9, 2022.

Going forward, “there’s no strong indication of a heat wave quite as strong as what we just experienced,” said James White, a meteorologist with the National Weather Service in Eureka, “but there also isn’t any sign of any significant relief. Just that droning, relentless, above-average temperature.”

The same conditions are prevailing in Lake County, he said, adding, “If anything, they started a couple days sooner, so they’ve been on this heat wave even longer.”

Sonoma County Fire District Division Chief and Marshal Cyndi Foreman said the extreme conditions were reflected in an uptick in heat-related emergency calls through the holidays, even as throngs of residents and visitors flocked to the Russian River and the coast seeking relief.

“Some of the typical heat-related issues that we will see is dehydration, overexposure to sun, people who may or may not have ingested alcohol. That can also be really challenging when you’re out in the heat, so there’s lots of factors that play into people having a severe reaction to some of these very high temperatures that we just can’t get away from.”

People with underlying health conditions also may react negatively to the heat, as well as “people that are maybe working in their yards and not calling it quits soon enough,” Foreman said.

In Santa Rosa, the temperature at the airport is forecast to rise to 92 on Monday before dipping Tuesday and rising again on Wednesday, Sarment said.

Napa, which enjoyed a relatively cool 79 degrees Sunday, as measured at the airport, also is forecast to head back to the mid-90s later this week.

“Again, just a slight cooldown, but it looks to warm back up starting Wednesday and Thursday,” Sarment said, “and then hopefully cool down into next weekend. That’s kind of what it looks like right now.”

You c an reach Staff Writer Mary Callahan (she/her) at 707-521-5249 or mary.callahan@pressdemocrat.com. On X (Twitter) @MaryCallahanB.