May in Wheaton averages a daily high of 21.8°C with nights around 9.3°C. Expect roughly 13.1 wet days totalling 109.6mm. 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. 27 years of May data.