May in Stolberg averages a daily high of 17.3°C with nights around 7.8°C. Expect roughly 13.5 wet days totalling 66.3mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Stolberg is June–September.
Based on NIDEGGEN SCHMIDT, GM (17.7km), 1995–2024. 30 years of May data.