September in Nichinan averages a daily high of 29.1°C. Expect roughly 14.9 wet days totalling 366.4mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Nichinan is October–December.
Based on ABURATSU, JA (3.7km), 1995–2024. 26 years of September data.