Extremely cold air to make it a nippy Bay Area weekend

The clearing of the Bay Area’s recent storms, and the ascension of high pressure in the region has brought with it a whole new concern.

It’s bitterly cold and getting colder.

“At first, we were putting out there that Friday was going to be the coldest day,” National Weather Service meteorologist Joe Merchant said early Thursday. “Now, we anticipate Saturday morning is going to be similar. Then Sunday will be on the cool side, too.”

Cold temperatures were expected when a pattern that brought several storms to the region from Christmas through the start of 2026 shifted to a dryer one. That new air from an air mass that descended from the north has been bolstered by increasing high pressure.

“The dryer air, the lack of clouds all make for more efficient cooling of the air,” Merchant said.

As a result, the weather service issued an extreme cold warning that starts at 1 a.m. Friday and lasts through 9 a.m. for the Marin hills, North Bay interior valleys, eastern Santa Clara hills, the interior of Monterey County and the Santa Lucia Range, most of San Benito county and the Southern Salinas Valley. Temperatures in those areas could fall into the low 30s and even the 20s, according to the weather service.

So far, a similar warning for Saturday is not in effect.

Temperatures on Friday and Saturday morning are not expected to rise past 40 degrees, and the daytime highs are not expected to escape the mid-50s.

“We sort of have a building of high pressure all across the West Coast, but it’s also progressive,” Merchant said. He said that pattern “eventually becomes zonal and keeps everything moving, so that the air doesn’t become stagnant.”

By Monday, the weather service said it expects the extreme cold snap to be over.

What they don’t expect is for the cold temperatures to keep people away from the beaches. And that could prove to be dangerous, too, Merchant said. Waves up to 22 feet high are expected along the coast, along with strong rip currents and sneaker waves. The weather service issued a high-surf advisory through 10 p.m. Friday and issued a hazardous beaches statement.

“With this really nice weather  after a long stretch of unsettled weather, people are going to be going to the beach,” Merchant said. “People need to stay off the walks and the cliffs and really be careful.”

Once the cold begins to lift on Monday, the sunny weather is expected to stay in place at least through the work week, according to the weather service.