In December, Niihama typically sees daytime highs of 8.6°C and overnight lows around 0.9°C. Compared to the annual average high of 17.0°C, December runs -8.4°C.
December in Niihama averages a daytime high of 8.6°C and an overnight low of 0.9°C.
December runs -8.4°C compared to Niihama's annual average high of 17.0°C, ranking #10 of 12 months by warmth.
Plan for daytime highs near 8.6°C and cooler evenings around 0.9°C.