September in Austin averages a daily high of 33.4°C with nights around 21.4°C. Expect roughly 6.6 wet days totalling 82.6mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Austin is October–April.
Based on AUSTIN CAMP MABRY, TX US (6.2km), 1995–2024. 30 years of September data.