December in Trondheim averages a daily high of 2°C with nights around -3.4°C. Expect roughly 16.7 wet days totalling 84.6mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Trondheim is June–August.
Based on TRONDHEIM VOLL, NO (3.6km), 1995–2024. 25 years of December data.