August in Berwyn averages a daily high of 28.3°C with nights around 19.3°C. Expect roughly 9.7 wet days totalling 98.4mm. Comfortable conditions for being outdoors all day.
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 August data.