In Sonoma County, homeless shelters handed out extra warm clothes to protect people from frigid overnight temperatures.
In the San Joaquin Valley, the heart of California's citrus production, growers prepared for another round of freezing temperatures early Sunday after seeing little crop damage since Thursday night.
"Last night was not a problem, but tonight and Monday morning could have the potential to be pretty cold," Paul Story, director of grower service at California Citrus Mutual, said Saturday.
Farmers run wind machines and water to protect their fruit, which can raise the temperature in a grove by up to 4 degrees, Story said. Existing moisture, sporadic rain and cloud cover can also help keep in heat.