December in Duluth averages a daily high of -2.5°C with nights around -10.1°C. Expect roughly 6.8 wet days totalling 36.3mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Duluth is June–September.
Based on SUPERIOR, WI US (6.8km), 1995–2024. 30 years of December data.