In September, Frederick typically sees daytime highs of 25.9°C and overnight lows around 13.3°C. Compared to the annual average high of 18.1°C, September runs +7.9°C.
September in Frederick averages a daytime high of 25.9°C and an overnight low of 13.3°C.
September runs +7.9°C compared to Frederick's annual average high of 18.1°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 25.9°C and cooler evenings around 13.3°C.