April in Gießen averages a daily high of 15.2°C with nights around 4°C. Expect roughly 10.8 wet days totalling 39.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Gießen is May–September.
Based on GIESSEN WETTENBERG, GM (2.3km), 1995–2024. 30 years of April data.