April in Koblenz averages a daily high of 15.3°C with nights around 3.6°C. Expect roughly 10.1 wet days totalling 38.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Koblenz is June–September.
Based on MONTABAUR, GM (18.7km), 1995–2024. 16 years of April data.