September in Ōtawara averages a daily high of 24.9°C. Expect roughly 12.9 wet days totalling 191.4mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Ōtawara is May–June.
Based on SHIRAKAWA, JA (33.8km), 1995–2024. 27 years of September data.