The calendar says it’s spring, but winter isn’t quite ready to call it a night.

A storm system moving across the Bay Area on Monday is delivering widespread showers, colder temperatures and even a chance of snow to the region’s highest mountaintops, according to the National Weather Service.

The prospect of snow on Mt. Diablo, Mt. Hamilton or Mt. Tamalpais in mid-April is unusual but not unprecedented, said Ryan Walbrun, a meteorologist with the weather service. Snow levels Monday could drop to 3,000 feet, and “If we can get a shower to line up” over one of the highest mountaintops, “we could see some white by the end of the day.”

“We get these last gasps of winter that drop down from Canada,” Walbrun said.

Temperatures across the Bay Area will struggle to reach 60 degrees. Scattered showers are expected through the afternoon.

“It’s going to be hit and miss,” Walbrun said. “Not everyone will get wet. But people could get stuck in a heavy downpour.”

There is also a chance of thunderstorms through Monday afternoon, which could also result in pea-sized hail, Walbruns said.

The storm hit the Bay Area on Sunday night, and the highest rainfall totals so far are north of the Golden Gate. As of 6 a.m., 24-hour rainfall totals include San Francisco .25 inches, Oakland .04 and San Jose .04.