May in Groningen averages a daily high of 17.8°C with nights around 7°C. Expect roughly 12.5 wet days totalling 57.6mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Groningen is May–September.
Based on EELDE, NL (10.7km), 1995–2024. 30 years of May data.