May in Vilnius averages a daily high of 18.2°C with nights around 7°C. Expect roughly 11.7 wet days totalling 46.6mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Vilnius is June–September.
Based on VILNIUS, LH (13.1km), 1995–2024. 19 years of May data.