December in Merced averages a daily high of 13.9°C with nights around 3°C. Expect roughly 9.1 wet days totalling 57.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Merced is April–May.
Based on MERCED, CA US (3.3km), 1995–2024. 25 years of December data.