August in Naperville averages a daily high of 28.1°C with nights around 16.9°C. Expect roughly 9.1 wet days totalling 94.7mm. Comfortable conditions for being outdoors all day.
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 August data.