In December, Santa Rosa typically sees daytime highs of 12.5°C and overnight lows around 2.8°C. Compared to the annual average high of 20.4°C, December runs -8.0°C.
December in Santa Rosa averages a daytime high of 12.5°C and an overnight low of 2.8°C.
December runs -8.0°C compared to Santa Rosa's annual average high of 20.4°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 12.5°C and cooler evenings around 2.8°C.