September in Arnsberg averages a daily high of 19.9°C with nights around 8°C. Expect roughly 11.7 wet days totalling 58.7mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Arnsberg is May–September.
Based on ARNSBERG NEHEIM, GM (11.6km), 1995–2024. 19 years of September data.