August in Dubuque averages a daily high of 28.1°C with nights around 17.6°C. Expect roughly 8.9 wet days totalling 90.3mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Dubuque is August–September.
Based on DUBUQUE LOCK AND DAM 11, IA US (4.6km), 1995–2024. 29 years of August data.