July in Dubuque averages a daily high of 29.3°C with nights around 18.4°C. Expect roughly 8.8 wet days totalling 129.1mm. Generally workable, with some weather to plan around.
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. 30 years of July data.