April in Jena averages a daily high of 16°C with nights around 4.4°C. Expect roughly 10.3 wet days totalling 35.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Jena is May–September.
Based on JENA STERNWARTE, GM (0.5km), 1995–2024. 30 years of April data.