May in Port Arthur averages a daily high of 29.8°C with nights around 19.9°C. Expect roughly 7.4 wet days totalling 128.7mm. 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 May data.