September in Houston averages a daily high of 32.1°C with nights around 22.8°C. Expect roughly 9.7 wet days totalling 144.3mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Houston is February–April.
Based on HOUSTON WILLIAM P HOBBY AIRPORT, TX US (15.2km), 1995–2024. 30 years of September data.