Heat wave brings record-breaking temperatures to Sonoma County this week

The mercury hit 97 on Tuesday in Santa Rosa, eclipsing a mark that has stood since 1974 and delivering what is expected to be the hottest day of a heat wave set to last most of this week in Sonoma County.

Santa Rosa is expected to set another record Wednesday, when the temperature is forecast to hit 95 degrees, according to Steve Anderson, meteorologist with the National Weather Service. Thursday’s high is expected to be in the lower 90s.

“We tied or broke seven records in the Bay Area (on Tuesday),” said Ryan Walbrun, another meteorologist with the weather service. “When you do that, it’s a unique day.”

Of the sites in Sonoma County where the National Weather Service tracks record highs, Santa Rosa was the only one to beat a record Tuesday, Walbrun said. The hottest spot in the county Tuesday was Geyserville, where the high reached 101 degrees.

Tuesday marked the third consecutive day of above-average heat, spanning the latter part of the Memorial Day weekend, when beaches along the Russian River were open - and crowded - but with pools shut and parks and beaches on the Sonoma Coast still closed because of the coronavirus.

By Friday, a sea breeze is forecast to bring temperatures back down near 80 degrees, with even milder weekend days in the low- to mid-70s. Warmer days are expected by the middle of next week, but nothing like the baking, high-pressure system that’s currently in place, Anderson said.

Social distancing guidelines and other safeguards mean that many places that would normally provide free air conditioning, such as libraries and malls, remain closed because of the shelter-in-place order meant to curb the spread of the coronavirus.

Both Anderson and Sonoma County Public Health Officer Dr. Sundari Mase advised residents at home to stay hydrated and avoid strenuous exercise during peak daytime temperatures. Residents could also take a cool bath or wrap a cold towel around their neck to combat the heat.

Anderson recommended people check in on their elderly neighbors or relatives, if they’re able, to make sure they’re safe.

“Heat stroke is something we really worry about, especially in older populations,” Mase said. “So try to stay cool.”

Northern Sonoma County saw the hottest weather in the area Tuesday, with Cloverdale and Healdsburg seeing highs of 100 degrees, Walbrun said.

Napa State Hospital broke its record of 98 degrees in 1896 by one degree Tuesday, falling just short of reaching triple digits, Walbrun said. But temperatures will likely surpass 100 degrees in some parts of Napa County later this week, prompting county health officials to advise residents to take precautions and check in on their elderly neighbors.

While skies will remain sunny and clear this week, there’s a small chance of some showers and even a thunderstorm on Saturday. But that brings with it some other concerns, Anderson said.

“The only significant danger would be any lightning that strikes the ground could start some fires after this prolonged, dry heat wave we’ve been in,” he said. “It still bears watching.”