December in Grand Forks averages a daily high of -5.7°C with nights around -14.2°C. Expect roughly 8.3 wet days totalling 21.5mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Grand Forks is May–September.
Based on GRAND FORKS UNIVERSITY NWS, ND US (4.8km), 1995–2024. 30 years of December data.