July in Wheaton averages a daily high of 28.9°C with nights around 17.1°C. Expect roughly 10.2 wet days totalling 96.2mm. Generally workable, with some weather to plan around.
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. 28 years of July data.