In September, Assen typically sees daytime highs of 18.6°C and overnight lows around 8.8°C. Compared to the annual average high of 12.9°C, September runs +5.7°C.
September in Assen averages a daytime high of 18.6°C and an overnight low of 8.8°C.
September runs +5.7°C compared to Assen's annual average high of 12.9°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 18.6°C and cooler evenings around 8.8°C.