In September, Mission Viejo typically sees daytime highs of 28.1°C and overnight lows around 14.9°C. Compared to the annual average high of 23.2°C, September runs +4.9°C.
September in Mission Viejo averages a daytime high of 28.1°C and an overnight low of 14.9°C.
September runs +4.9°C compared to Mission Viejo's annual average high of 23.2°C, ranking #3 of 12 months by warmth.
Plan for daytime highs near 28.1°C and cooler evenings around 14.9°C.