In December, Joliet typically sees daytime highs of 1.8°C and overnight lows around -6.6°C. Compared to the annual average high of 15.3°C, December runs -13.5°C.
December in Joliet averages a daytime high of 1.8°C and an overnight low of -6.6°C.
December runs -13.5°C compared to Joliet's annual average high of 15.3°C, ranking #10 of 12 months by warmth.
Plan for daytime highs near 1.8°C and cooler evenings around -6.6°C.