July in Berwyn averages a daily high of 29.4°C with nights around 20°C. Expect roughly 9.9 wet days totalling 98.6mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Berwyn is May–June.
Based on CHICAGO MIDWAY AIRPORT, IL US (8km), 1995–2024. 28 years of July data.