In December, West Allis typically sees daytime highs of -0.7°C and overnight lows around -8.4°C. Compared to the annual average high of 12.9°C, December runs -13.6°C.
December in West Allis averages a daytime high of -0.7°C and an overnight low of -8.4°C.
December runs -13.6°C compared to West Allis's annual average high of 12.9°C, ranking #10 of 12 months by warmth.
Plan for daytime highs near -0.7°C and cooler evenings around -8.4°C.