May in Ljubljana averages a daily high of 21.9°C with nights around 10.7°C. Expect roughly 13.1 wet days totalling 122.7mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Ljubljana is May–September.
Based on LJUBLJANA BEZIGRAD, SI (1.9km), 1995–2024. 30 years of May data.