Southern California storm triggers rare August rainfall in North Bay

Rainfall in August is a rare occurrence in Sonoma County, according to Sean Miller, a meteorologist with the National Weather Service in Monterey.

“This is typically the drier time of the year,” he said.

The small amount of rain that fell across the North Bay region on Monday was the result of monsoonal weather conditions hundreds of miles to the south.

According to the National Weather Service, about 0.10 of an inch was expected in the North Bay and other parts of the Bay Area by nighttime.

It was a drop in the bucket compared to the day’s precipitation in Southern California, where the mountain regions recorded more than an inch of rain by the afternoon, causing flood watches in some areas.

Over the past 20 years in Sonoma County, there have been two measurable instances of August rainfall, one in 2015 and again in 2020. Both were recorded at the Charles M. Schulz—Sonoma County Airport, according to National Weather Service data.

In 2015, there was 0.03 of an inch of rain on Aug. 29. That was followed in 2020 with 0.06 iof an inch on Aug. 16 and 0.03 inches on Aug. 17.

Drier conditions are expected for the rest of the week.

Temperatures are expected to reach the low-80s through Wednesday before inching into the upper 80s by the weekend.

Monday’s rain won’t ease drought conditions but should temporarily stave off concerns about fires, Miller said.

You can reach Staff Writer Colin Atagi at colin.atagi@pressdemocrat.com. On Twitter @colin_atagi