Temperatures in Pleasanton and the Bay Area are expected to drop in the coming days followed by wet weather later in the week.
The National Weather Service predicts that the chilliest temperatures last night will linger into Wednesday morning.
Temperatures throughout the region Wednesday morning are forecast to range from the low 30s and low 40s.
The cold weather may cause patchy frost in some areas, possibly resulting in slick roadways.
Rain will follow, beginning with off-and-on showers Wednesday evening, which will last through the weekend. Some parts of the Bay Area are expected to receive between 0.90 and 1.90 inches of rain, weather service officials said.