In December, Heidelberg typically sees daytime highs of 4.3°C and overnight lows around -0.7°C. Compared to the annual average high of 14.2°C, December runs -9.9°C.
December in Heidelberg averages a daytime high of 4.3°C and an overnight low of -0.7°C.
December runs -9.9°C compared to Heidelberg's annual average high of 14.2°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 4.3°C and cooler evenings around -0.7°C.