September in Sanya averages a daily high of 30.3°C with nights around 23.6°C. Expect roughly 18.6 wet days totalling 340.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Sanya is November–March.
Based on SANYA, CH (8.8km), 1995–2024. 22 years of September data.