In September, San Antonio typically sees daytime highs of 27.7°C and overnight lows around 15.3°C. Compared to the annual average high of 28.9°C, September runs -1.1°C.
September in San Antonio averages a daytime high of 27.7°C and an overnight low of 15.3°C.
September runs -1.1°C compared to San Antonio's annual average high of 28.9°C, ranking #8 of 12 months by warmth.
Plan for daytime highs near 27.7°C and cooler evenings around 15.3°C.