In September, Skien typically sees daytime highs of 15.2°C and overnight lows around 8.1°C. Compared to the annual average high of 9.6°C, September runs +5.7°C.
September in Skien averages a daytime high of 15.2°C and an overnight low of 8.1°C.
September runs +5.7°C compared to Skien's annual average high of 9.6°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 15.2°C and cooler evenings around 8.1°C.