September in Kiel averages a daily high of 18.7°C with nights around 10.8°C. Expect roughly 12.9 wet days totalling 59.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Kiel is June–September.
Based on KIEL HOLTENAU, GM (6.1km), 1995–2024. 25 years of September data.