How hot is California in December?

California's temperatures can vary based on region and elevation in December. On average, coastal areas of California such as San Francisco and Los Angeles experience mild, moderate weather with average temperatures ranging from 45°F (7°C) to 60°F (16°C). Inland valleys like the Central Valley tend to be warmer, with daytime temperatures usually hovering around 55°F (13°C) to 65°F (18°C). While mountain areas, particularly in the Sierra Nevada and Cascade Ranges, often see temperatures below freezing at night and have occasional snowfall. Additionally, extreme weather events such as storms, cold fronts, or Santa Ana winds can bring temperatures higher or lower than these averages.