Wet, cool conditions were expected to continue in Pinole and Hercules through Sunday evening, with a chance of clearing by Monday, according to forecasters with the National Weather Service.
Contra Costa County roads including San Pablo Avenue and Interstate 80 were soaked and public safety agencies advised motorists to plan extra time for the rain and slick conditions.
"It's heading through the Bay area and it's not at all unsual for this time of year," Weather Service forecaster Diana Henderson said in a phone interview from Monterey.
"Our roads are wet, there could be some ponding, so slow down," Henderson said.
Along with the rain, southeast winds around 6 miles per hour were expected Friday, according to the Weather Service.
The high for Pinole and Hercules on Friday was expected around 62, with overnight lows into Saturday in the high 50s.
As of 1 p.m. Friday, a flood advisory and hazardous weather outlook updates were available for Pinole and Hercules.
In Hercules, sandbag stations were set up in the City Hall parking lot and the right-rear of the Community Center's parking lot, according to the city.