December in Wheaton averages a daily high of 2.3°C with nights around -6°C. Expect roughly 8.8 wet days totalling 42.6mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Wheaton is May–June.
Based on CHICAGO WEST CHICAGO DUPAGE AIRPORT, IL US (12.4km), 1995–2024. 27 years of December data.