December in Santa Maria averages a daily high of 18°C with nights around 4.6°C. Expect roughly 7.7 wet days totalling 55.6mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Santa Maria is April–November.
Based on SANTA MARIA PUBLIC AIRPORT, CA US (6.7km), 1995–2024. 30 years of December data.