In December, Casper typically sees daytime highs of 2.6°C and overnight lows around -9.3°C. Compared to the annual average high of 15.2°C, December runs -12.6°C.
December in Casper averages a daytime high of 2.6°C and an overnight low of -9.3°C.
December runs -12.6°C compared to Casper's annual average high of 15.2°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 2.6°C and cooler evenings around -9.3°C.