In January, Costa Mesa typically sees daytime highs of 18.4°C and overnight lows around 7.8°C. Compared to the annual average high of 22.1°C, January runs -3.7°C.
January in Costa Mesa averages a daytime high of 18.4°C and an overnight low of 7.8°C.
January runs -3.7°C compared to Costa Mesa's annual average high of 22.1°C, ranking #12 of 12 months by warmth.
Plan for daytime highs near 18.4°C and cooler evenings around 7.8°C.