December in Trier averages a daily high of 5.2°C with nights around 0.7°C. Expect roughly 16.3 wet days totalling 71.6mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Trier is May–September.
Based on TRIER PETRISBERG, GM (1.6km), 1995–2024. 30 years of December data.