April in Heilbronn averages a daily high of 16.7°C with nights around 4.7°C. Expect roughly 11.1 wet days totalling 48mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Heilbronn is May–September.
Based on OBERSULM WILLSBACH, GM (9.7km), 1995–2024. 20 years of April data.