https://www.mercurynews.com/2023/01/30/frost-advisory-in-effect-as-frigid-temperatures-expected-monday-night/

Slight rainfall Sunday combined with frigid overnight temperatures to kick off what’s expected to be a chilly first half of the week, with lows forecast to dip below 30 degrees in parts of the Bay Area Monday night.

Scattered showers passed through some Bay Area cities Sunday afternoon and evening. Twenty-four hour rain totals from the National Weather Service at 7 a.m. Monday showed slightly more than half of an inch of rain at Mt. Diablo in Contra Costa County, .04 inches in Milpitas,  and .02 at San Francisco International Airport and Fremont. Oakland, Downtown San Francisco and San Jose remained virtually dry.