January in Heilbronn averages a daily high of 5.1°C with nights around -0.7°C. Expect roughly 15 wet days totalling 60.3mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Heilbronn is May–September.
Based on OBERSULM WILLSBACH, GM (9.7km), 1995–2024. 20 years of January data.