In September, Alpharetta typically sees daytime highs of 27.8°C and overnight lows around 16.0°C. Compared to the annual average high of 21.5°C, September runs +6.3°C.
September in Alpharetta averages a daytime high of 27.8°C and an overnight low of 16.0°C.
September runs +6.3°C compared to Alpharetta's annual average high of 21.5°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 27.8°C and cooler evenings around 16.0°C.