December in Marl averages a daily high of 6.5°C with nights around 1.7°C. Expect roughly 18.9 wet days totalling 86.8mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Marl is May–September.
Based on BOCHUM, GM (23.2km), 1995–2024. 13 years of December data.