In September, Cergy-Pontoise typically sees daytime highs of 20.3°C and overnight lows around 9.8°C. Compared to the annual average high of 14.6°C, September runs +5.7°C.
September in Cergy-Pontoise averages a daytime high of 20.3°C and an overnight low of 9.8°C.
September runs +5.7°C compared to Cergy-Pontoise's annual average high of 14.6°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 20.3°C and cooler evenings around 9.8°C.