In January, Petaluma typically sees daytime highs of 12.3°C and overnight lows around 4.1°C. Compared to the annual average high of 18.5°C, January runs -6.2°C.
January in Petaluma averages a daytime high of 12.3°C and an overnight low of 4.1°C.
January runs -6.2°C compared to Petaluma's annual average high of 18.5°C, ranking #12 of 12 months by warmth.
Plan for daytime highs near 12.3°C and cooler evenings around 4.1°C.