In January, San Mateo typically sees daytime highs of 28.6°C and overnight lows around 21.6°C. Compared to the annual average high of 30.4°C, January runs -1.8°C.
January in San Mateo averages a daytime high of 28.6°C and an overnight low of 21.6°C.
January runs -1.8°C compared to San Mateo's annual average high of 30.4°C, ranking #12 of 12 months by warmth.
Plan for daytime highs near 28.6°C and cooler evenings around 21.6°C.