August in Siegen averages a daily high of 24.4°C with nights around 11.1°C. Expect roughly 12.5 wet days totalling 73.5mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Siegen is May–September.
Based on DILLENBURG, GM (23.1km), 1995–2024. 27 years of August data.