May in Willich averages a daily high of 19.7°C with nights around 8.9°C. Expect roughly 12.8 wet days totalling 65.4mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Willich is May–September.
Based on TONISVORST, GM (7.7km), 1995–2024. 30 years of May data.