The National Weather Service reports that San Francisco's low of 42 degrees on Thursday tied a record set back in 1892. Across the bay in Oakland, 36-degree daytime temperatures shattered the old record of 42.
The mercury in Los Angeles dropped to 42, tying a 1946 record.
Stockton saw a record low temperature of 27 degrees Thursday morning, while Sacramento tied a record low of 30.
Subfreezing temperatures in California's Central Valley citrus growing region threatened to damage the billion-dollar crop. But growers working through the night used warm water and wind machines to keep the cold at bay.