Cool temps headed to the North Bay. Here’s how far below normal they’ll be

On the heels of this past weekend’s heat wave in which the North Bay’s prolonged highs topped out in the 90s, temperatures are now expected to plunge, triggering an early week shower in parts of the region, according to the National Weather Service.

Meteorologists predict a 70% chance Monday of rainfall that will deposit as much as one-tenth of an inch in the valleys, particularly in Santa Rosa and Rohnert Park, according to the area forecast discussion Sunday evening.

Areas such as Healdsburg, Cloverdale and Calistoga could see less than that amount. Bodega Bay, which could have spots of rain through Tuesday night, is expected to get at least ¼ of an inch.

The showers will fade Monday night, though in some parts of the region the rain could linger into Tuesday morning.

Temperatures began cooling slightly Sunday along the coast as the marine layer rebuilt, bringing more clouds and humidity. Inland highs on Monday won’t reach past reach the mid-60s, according to the weather service.

The cold front, which is set to trigger the rains, is the cause of the cooler temps in the interior valleys. The highs are expected to be as much as 10 to 15 degrees below normal, according to the weather service.

This drop might feel even more “drastic” following the region’s recent trip into the 90s, meteorologists said.

On Monday, the high will be 66 in Santa Rosa, 67 in Windsor and St. Helena, and 60 in Bodega Bay.

The high recorded Friday at the Charles M. Schulz-Sonoma County Airport set a record at 97 degrees.

As the cold front fades from the North Bay, temperatures are expected to gradually climb and return to normal highs hovering in the upper-70s to low-80s by Thursday.

Friday will be fairly uneventful, according to the weather service, until Saturday when yet another chance of rain looms.

It will likely not drop as much rain on the region as Monday’s predicted rains, according to the weather service.

You can reach Staff Writer Madison Smalstig at madison.smalstig@pressdemocrat.com. On Twitter @madi.smals.