September in Ōta averages a daily high of 28.1°C. Expect roughly 12.4 wet days totalling 192.4mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Ōta is April–May.
Based on KUMAGAYA, JA (16.7km), 1995–2024. 25 years of September data.