A high-pressure weather system has settled into place over the Bay Area and Northern California and is building. Clouds have evaporated into practically nothing and are expected to stay gone. Temperatures are rising.

A bit of a heat wave in the middle of winter?

“Yes, I would say it is,” National Weather Service meteorologist Roger Gass said Wednesday. “That’s a fair thing to say.”

The warming trend also is bringing with it another staple of the summer heat waves. The Bay Area Air District on Wednesday issued a Spare the Air alert that will be in effect Wednesday. It’s the second such alert issued in 2026.

Wood-burning is illegal on such days. Not that a lot of warmth is expected to be needed in many places.

“We are expecting temperatures along the Central Coast to warm up into the 70s until about Saturday and there may be some higher-elevation spots that get into the high 70s,” Gass said. “Generally closer to the (San Francisco) Bay, we expect temperatures to be from the upper 60s to maybe the lower 60s in some places.

In all, the weather service said temperatures are expected to be about 10-15 degrees warmer than normal along the central coast and 5-8 degrees warmer than normal closer to the central Bay Area. The build in temperatures followed a cold snap last week that brought the weather service’s first-ever extreme cold warning.

It’s also expected to bring more people than normal to the area beaches, and that could be dangerous. The weather service said rip currents and sneaker waves are expected to be plentiful this weekend and put out a beach hazards statement from 10 a.m. Wednesday until 9 p.m. Friday night.

The high pressure is expected to “stay in place” until about Saturday, Gass said. Until then, it’s likely that air pollution could be trapped lower to the atmosphere and the air quality could suffer. The air district said it expects air quality throughout the region to be only moderately healthy on Thursday, and it has a similar forecast for Friday.

By Saturday, the high pressure is expected to break down a bit and cloudier and cooler days are expected early next week. The weather service said it does not expect rain in the region anytime over the next seven days.