December in Champaign averages a daily high of 3.9°C with nights around -4.4°C. Expect roughly 10.6 wet days totalling 65.2mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Champaign is September.
Based on CHAMPAIGN 3 S, IL US (3.6km), 1995–2024. 30 years of December data.