September in Mostar averages a daily high of 27.6°C with nights around 16.2°C. Expect roughly 8.4 wet days totalling 128.7mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Mostar is April–May.
Based on MOSTAR, BK (1km), 1995–2024. 16 years of September data.