In September, National City typically sees daytime highs of 26.2°C and overnight lows around 16.0°C. Compared to the annual average high of 22.1°C, September runs +4.1°C.
September in National City averages a daytime high of 26.2°C and an overnight low of 16.0°C.
September runs +4.1°C compared to National City's annual average high of 22.1°C, ranking #2 of 12 months by warmth.
Plan for daytime highs near 26.2°C and cooler evenings around 16.0°C.