Snow made it to the Bay Area on Monday.
As the National Weather Service predicted, snow was falling in some of the region's higher elevations such as Mount Hamilton, Mount Diablo and Mount Tamalpais.
Between late Monday afternoon and Tuesday morning, the snow could reach as far down as 400 to 1,000 feet and possibly as low as sea level, especially in the North Bay, the weather service said.
The North Bay mountains, East Bay hills and Santa Cruz mountains may see 2-4 inches of snow above 1,000 feet and 4-8 inches in areas above 2,000 feet between late Monday afternoon and Tuesday morning, according to the weather service.
Potential hazardous driving conditions are expected on Highway 35 (Skyline Boulevard) in the Santa Cruz Mountains, Highways 9, 17, 29, 130 and Grizzly Peak Boulevard in the Berkeley Hills between Monday afternoon and Tuesday morning.
Temperatures Monday night will range from the low 30s to low 40s region wide, and lows on Tuesday and Wednesday nights will be in the upper 20s to upper 30s region wide. San Francisco should be around 40 degrees, the National Weather Service said.
The cold temperatures Tuesday and Wednesday nights will threaten vulnerable populations, sensitive vegetation and outdoor animals.
Light to moderate rainfall is predicted, and stronger showers and isolated thunderstorms may bring brief heavy rain with possible hail and lightning.
Rain amounts will be less than an inch in urban locations and up to an inch and 1.5 inches in the wettest locations. Showers will decrease Tuesday, the weather service said.
Feb. 5 has historically been a good day for snowfall in San Francisco. On Feb. 5 1887, 3.7 inches fell during the day - up to 7 inches on Twin Peaks and 5 inches in the downtown area.
On Feb. 5, 1976, San Francisco received an inch of snow and up to 5 inches on Twin Peaks.
On New Year's Eve in 1882, 3.5 inches fell in the City between 11:30 a.m. and 4:20 p.m.
There have been 11 days when snow was recorded near sea level in San Francisco.