In December, Petaluma typically sees daytime highs of 12.7°C and overnight lows around 4.3°C. Compared to the annual average high of 18.5°C, December runs -5.8°C.
December in Petaluma averages a daytime high of 12.7°C and an overnight low of 4.3°C.
December runs -5.8°C compared to Petaluma's annual average high of 18.5°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 12.7°C and cooler evenings around 4.3°C.