In January, Napa typically sees daytime highs of 12.3°C and overnight lows around 2.4°C. Compared to the annual average high of 21.5°C, January runs -9.3°C.
January in Napa averages a daytime high of 12.3°C and an overnight low of 2.4°C.
January runs -9.3°C compared to Napa's annual average high of 21.5°C, ranking #12 of 12 months by warmth.
Plan for daytime highs near 12.3°C and cooler evenings around 2.4°C.