January in Gießen averages a daily high of 3.9°C with nights around -1.2°C. Expect roughly 14 wet days totalling 49mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Gießen is May–September.
Based on GIESSEN WETTENBERG, GM (2.3km), 1995–2024. 30 years of January data.