In December, Idaho Falls typically sees daytime highs of 0.3°C and overnight lows around -9.8°C. Compared to the annual average high of 14.5°C, December runs -14.1°C.
December in Idaho Falls averages a daytime high of 0.3°C and an overnight low of -9.8°C.
December runs -14.1°C compared to Idaho Falls's annual average high of 14.5°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 0.3°C and cooler evenings around -9.8°C.