December in Basel averages a daily high of 5.8°C with nights around 0.4°C. Expect roughly 14.4 wet days totalling 64.7mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Basel is June–September.
Based on BASEL BINNINGEN, SZ (2.9km), 1995–2024. 30 years of December data.