September in Zhoushan averages a daily high of 28.5°C with nights around 22°C. Expect roughly 11.5 wet days totalling 192.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Zhoushan is October.
Based on DINGHAI, CH (9.8km), 1995–2024. 23 years of September data.