December in Ŭndŏk averages a daily high of -2.6°C with nights around -10.1°C. Expect roughly 3.3 wet days totalling 12.2mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Ŭndŏk is September.
Based on POSET, RS (40.8km), 1995–2024. 30 years of December data.