In September, Trondheim typically sees daytime highs of 13.5°C and overnight lows around 5.8°C. Compared to the annual average high of 8.4°C, September runs +5.1°C.
September in Trondheim averages a daytime high of 13.5°C and an overnight low of 5.8°C.
September runs +5.1°C compared to Trondheim's annual average high of 8.4°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 13.5°C and cooler evenings around 5.8°C.