In September, Surprise typically sees daytime highs of 37.3°C and overnight lows around 20.8°C. Compared to the annual average high of 29.7°C, September runs +7.6°C.
September in Surprise averages a daytime high of 37.3°C and an overnight low of 20.8°C.
September runs +7.6°C compared to Surprise's annual average high of 29.7°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 37.3°C and cooler evenings around 20.8°C.