September in Port Arthur averages a daily high of 31.8°C with nights around 21.6°C. Expect roughly 8.9 wet days totalling 168.7mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Port Arthur is February–April.
Based on PORT ARTHUR SE TX REGIONAL AIRPORT, TX US (11km), 1995–2024. 30 years of September data.