San Francisco might drop beneath 40 levels on Tuesday

San Francisco reached 46 degrees on Monday morning when a cold breeze from western Canada penetrated the region, the National Weather Service said. Conditions are expected to cool even further from Monday night to Tuesday morning.

“Downtown SF has the potential to drop below 40 degrees on Tuesday morning,” wrote the weather service on Twitter. “The last day this happened was January 6, 2017 (minimum temperature was 39). #CAwx.”

With the cold air moving in, snow depths around the Bay Area could drop to as much as 300 meters inland by early Tuesday and as much as 250 to 150 meters in the valleys of the North Bay.

Could we see snow in San Francisco?

“I think there are parts of the Bay Area that have the potential for a few snowstorms to hit the surface, but in places along the bay like San Francisco that seems very unlikely,” said Roger Gass, a forecaster for the weather service.

It snowed an inch to two inches on the streets of San Francisco on February 5, 1976, pollinating the Marin Headlands, north of the Golden Gate Bridge.

Kunst Frisch / Hearst

Snow has fallen and stuck on the ground 11 times in San Francisco, according to records dating back to the gold rush. During a recent cold snap on February 5, 2019, a weather observer spotted snow on the Twin Peaks, but it did not stick and was not one of the 11 on February 5, 1976 when Twin Peaks iced up to 5 inches. This event was well photographed and pictures show people all over town throwing snowballs and building snowmen.

February 5, 1887 was reputedly the snowiest day for the city at 3.7 inches on record at the National Weather Service’s office in the Financial District of San Francisco. The top of the twin peaks is matted up to seven inches. In fact, it did snow a couple of times on February 5th, making it the snowiest day of the year in SF history.

Snow fell only twice in December. On December 31, 1882, it was a staggering 3.5 inches and snow fell from 11:30 a.m. to 4:20 p.m. Less than an inch was recorded on December 11, 1932.

The National Weather Service shared a map showing where snow might fall in the SF Bay Area in the coming days.

NWS

While snow is unlikely in San Francisco on Tuesday, fresh powder is expected in other areas of the Bay Area. The weather service has shared a map showing where snow is likely to fall (see map above).

The official snow forecast from the Meteorological Service said, “Snow depths will generally be between 1,500 and 3,000 feet this week. The exception is Tuesday morning, when we expect the coldest air at altitude and snow depths will be significantly lower, you will see snow depths of up to 250-500 ft above North Bay on Tuesday morning. That means the potential for a rain-snow mix could reach some of the North Bay Valley locations [region] will have snow depths of up to 1000-2000 ft on Tuesday morning. “

Given the cold temperatures in the mix, Gass noted that people should look for family members and neighbors who don’t have adequate sources of heat.

“Make sure you protect sensitive plants and animals outdoors,” warned the weather service. “Also note that roads that are wet in the early hours of the morning can become icy in places if we step into this colder pattern.”