May in Trier averages a daily high of 19.7°C with nights around 8.7°C. Expect roughly 13 wet days totalling 68.8mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Trier is May–September.
Based on TRIER PETRISBERG, GM (1.6km), 1995–2024. 30 years of May data.