April in Hamm averages a daily high of 15.2°C with nights around 4.4°C. Expect roughly 10.4 wet days totalling 39.8mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Hamm is May–September.
Based on WERL, GM (12.3km), 1995–2024. 21 years of April data.