In December, Allentown typically sees daytime highs of 4.3°C and overnight lows around -4.7°C. Compared to the annual average high of 16.2°C, December runs -11.9°C.
December in Allentown averages a daytime high of 4.3°C and an overnight low of -4.7°C.
December runs -11.9°C compared to Allentown's annual average high of 16.2°C, ranking #10 of 12 months by warmth.
Plan for daytime highs near 4.3°C and cooler evenings around -4.7°C.