May in Lappeenranta averages a daily high of 15.8°C with nights around 6.3°C. Expect roughly 9.8 wet days totalling 40.6mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Lappeenranta is June–August.
Based on LAPPEENRANTA LEPOLA, FI (1.3km), 1995–2024. 17 years of May data.