September in Hà Tiên averages a daily high of 29.9°C. Expect roughly 22 wet days totalling 508mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Hà Tiên is December–February.
Based on PHU QUOC, VM (59.9km), 1995–2024. 13 years of September data.