At this time of year, the west coast state of California is mild and damp, bringing cooler temperatures, scattered rain showers and cloudy days. You’ll still have plenty of sunny spells though. Los Angeles is still relatively warm in December, especially compared with the chilly UK winters, while further north in San Francisco the temperatures are slightly cooler and rain is more frequent.
In December, the average temperature in San Francisco is 10ºC, with highs of 13ºC and lows of 8ºC at night. Los Angeles is a little warmer this month, with mild temperatures of 14ºC on average, along with highs of 19ºC in the peak of the afternoon. California is quite wet at this time of year, with San Francisco expecting around 110mm of rain and Los Angeles around 65mm.