May in Arnsberg averages a daily high of 18.6°C with nights around 5.5°C. Expect roughly 13.8 wet days totalling 69.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Arnsberg is May–September.
Based on ARNSBERG NEHEIM, GM (11.6km), 1995–2024. 19 years of May data.