July in Bonn averages a daily high of 24.2°C with nights around 13.7°C. Expect roughly 13.8 wet days totalling 84.5mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Bonn is May–September.
Based on BONN ROLEBER, GM (6.9km), 1995–2024. 24 years of July data.