August in Hamm averages a daily high of 24.1°C with nights around 13.2°C. Expect roughly 14.3 wet days totalling 81mm. 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 August data.