In Mountain View, temperatures dipped to 32 degrees Thursday morning, breaking a 15-year record, according to the National Weather Service.
"We're finally getting our winter," said National Weather Service forecaster Steve Anderson.
Anderson said temperatures are expected to rise slightly on Friday morning, but that rain is expected on Saturday, as well as snow above 2,500 feet throughout the Bay Area.
He said motorists in the region should drive with extra caution on Saturday night and Sunday morning, when runoff from rain and snow is expected to create icy patches on area roadways.
Warmer temperatures are expected next week.
The cold snap is the result of a high-pressure cold air mass that originated in Northern Canada.