In September, La Mesa typically sees daytime highs of 27.1°C and overnight lows around 15.4°C. Compared to the annual average high of 22.5°C, September runs +4.6°C.
September in La Mesa averages a daytime high of 27.1°C and an overnight low of 15.4°C.
September runs +4.6°C compared to La Mesa's annual average high of 22.5°C, ranking #2 of 12 months by warmth.
Plan for daytime highs near 27.1°C and cooler evenings around 15.4°C.