December weather forecast and climate
California, USA

December lies in the cold of winter with the average high temperatures in the 55°F (12.8°C) to 60°F (15.6°C) range and the average low temperatures in the mildly cold 37°F (2.8°C) to 45°F (7.2°C) range across the northern parts of the state. Southern parts of California are a little warmer than the north with the average highs of 60°F (15.6°C) to 68°F (20°C) and the average lows of 45°F (7.2°C) to 55°F (12.8°C).
December is rainy with an average of 3" (76mm) of rain; San Rafael in the north is one of the wettest places in the state with 7.6" (193mm) of precipitation.
Snow falls in large amounts in the mountains of Sierra Nevada, while it is meager along the coast and lowlands. Sunshine is usually up to 6 hours due to an increase in cloud cover and humidity that goes above 78%. The winter is cold, but temperatures do not drop below freezing in most parts of the state.
The period after Thanksgiving Day usually does not see many visitors to California due to the damp and cold conditions.