In September, Santa Rosa typically sees daytime highs of 23.6°C and overnight lows around 13.1°C. Compared to the annual average high of 25.7°C, September runs -2.1°C.
September in Santa Rosa averages a daytime high of 23.6°C and an overnight low of 13.1°C.
September runs -2.1°C compared to Santa Rosa's annual average high of 25.7°C, ranking #8 of 12 months by warmth.
Plan for daytime highs near 23.6°C and cooler evenings around 13.1°C.