May in Ahlen averages a daily high of 18.9°C with nights around 7.6°C. Expect roughly 13 wet days totalling 62.1mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Ahlen is May–September.
Based on WERL, GM (20.6km), 1995–2024. 21 years of May data.