May in Deventer averages a daily high of 18.4°C with nights around 7.2°C. Expect roughly 12.4 wet days totalling 60.7mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Deventer is May–September.
Based on HEINO, NL (20.9km), 1995–2024. 30 years of May data.