In September, Galveston typically sees daytime highs of 29.6°C and overnight lows around 23.3°C. Compared to the annual average high of 24.1°C, September runs +5.5°C.
September in Galveston averages a daytime high of 29.6°C and an overnight low of 23.3°C.
September runs +5.5°C compared to Galveston's annual average high of 24.1°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 29.6°C and cooler evenings around 23.3°C.