In September, Heidelberg typically sees daytime highs of 24.4°C and overnight lows around 6.9°C. Compared to the annual average high of 23.2°C, September runs +1.1°C.
September in Heidelberg averages a daytime high of 24.4°C and an overnight low of 6.9°C.
September runs +1.1°C compared to Heidelberg's annual average high of 23.2°C, ranking #7 of 12 months by warmth.
Plan for daytime highs near 24.4°C and cooler evenings around 6.9°C.