In September, San Antonio typically sees daytime highs of 32.5°C and overnight lows around 20.4°C. Compared to the annual average high of 26.8°C, September runs +5.7°C.
September in San Antonio averages a daytime high of 32.5°C and an overnight low of 20.4°C.
September runs +5.7°C compared to San Antonio's annual average high of 26.8°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 32.5°C and cooler evenings around 20.4°C.