In December, Vallejo typically sees daytime highs of 13.6°C and overnight lows around 3.9°C. Compared to the annual average high of 20.8°C, December runs -7.2°C.
December in Vallejo averages a daytime high of 13.6°C and an overnight low of 3.9°C.
December runs -7.2°C compared to Vallejo's annual average high of 20.8°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 13.6°C and cooler evenings around 3.9°C.