In September, Terni typically sees daytime highs of 25.2°C and overnight lows around 12.7°C. Compared to the annual average high of 18.4°C, September runs +6.7°C.
September in Terni averages a daytime high of 25.2°C and an overnight low of 12.7°C.
September runs +6.7°C compared to Terni's annual average high of 18.4°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 25.2°C and cooler evenings around 12.7°C.