In January, South San Francisco typically sees daytime highs of 12.9°C and overnight lows around 5.4°C. Compared to the annual average high of 17.7°C, January runs -4.8°C.
January in South San Francisco averages a daytime high of 12.9°C and an overnight low of 5.4°C.
January runs -4.8°C compared to South San Francisco's annual average high of 17.7°C, ranking #12 of 12 months by warmth.
Plan for daytime highs near 12.9°C and cooler evenings around 5.4°C.