In September, Duluth typically sees daytime highs of 18.4°C and overnight lows around 6.9°C. Compared to the annual average high of 9.3°C, September runs +9.0°C.
September in Duluth averages a daytime high of 18.4°C and an overnight low of 6.9°C.
September runs +9.0°C compared to Duluth's annual average high of 9.3°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 18.4°C and cooler evenings around 6.9°C.