December in Naperville averages a daily high of 2.5°C with nights around -5.9°C. Expect roughly 9.9 wet days totalling 55.7mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Naperville is August–September.
Based on AURORA WATER, IL US (13.4km), 1995–2024. 30 years of December data.