In December, Wheaton typically sees daytime highs of 1.1°C and overnight lows around -7.1°C. Compared to the annual average high of 14.7°C, December runs -13.6°C.
December in Wheaton averages a daytime high of 1.1°C and an overnight low of -7.1°C.
December runs -13.6°C compared to Wheaton's annual average high of 14.7°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 1.1°C and cooler evenings around -7.1°C.