September in Liège averages a daily high of 20.1°C with nights around 10.8°C. Expect roughly 11.1 wet days totalling 57.6mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Liège is May–September.
Based on MAASTRICHT, NL (33.1km), 1995–2024. 30 years of September data.