September in Ljubljana averages a daily high of 22°C with nights around 11.8°C. Expect roughly 10.9 wet days totalling 168.1mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Ljubljana is May–September.
Based on LJUBLJANA BEZIGRAD, SI (1.9km), 1995–2024. 30 years of September data.