In December, Guidonia Montecelio typically sees daytime highs of 12.8°C and overnight lows around 3.8°C. Compared to the annual average high of 20.9°C, December runs -8.0°C.
December in Guidonia Montecelio averages a daytime high of 12.8°C and an overnight low of 3.8°C.
December runs -8.0°C compared to Guidonia Montecelio's annual average high of 20.9°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 12.8°C and cooler evenings around 3.8°C.