In October, Costa Mesa typically sees daytime highs of 24.2°C and overnight lows around 13.4°C. Compared to the annual average high of 22.1°C, October runs +2.1°C.
October in Costa Mesa averages a daytime high of 24.2°C and an overnight low of 13.4°C.
October runs +2.1°C compared to Costa Mesa's annual average high of 22.1°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 24.2°C and cooler evenings around 13.4°C.