September in San Antonio averages a daily high of 32.3°C with nights around 20.4°C. Expect roughly 7.5 wet days totalling 107.7mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit San Antonio is February–April.
Based on SAN ANTONIO INCARNATE WORD, TX US (5.5km), 1995–2024. 24 years of September data.