April in Bonn averages a daily high of 15.5°C with nights around 5.1°C. Expect roughly 11.1 wet days totalling 46.1mm. 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. 23 years of April data.