May in Kouvola averages a daily high of 16.2°C with nights around 4.9°C. Expect roughly 10.1 wet days totalling 42.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Kouvola is May–August.
Based on KOUVOLA UTTI LENTOPORTINTIE, FI (13.5km), 1995–2024. 30 years of May data.