August in Koblenz averages a daily high of 23.3°C with nights around 11.9°C. Expect roughly 12.9 wet days totalling 73.5mm. 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. 17 years of August data.