In September, Santa Rosa typically sees daytime highs of 30.9°C and overnight lows around 23.9°C. Compared to the annual average high of 31.2°C, September runs -0.3°C.
September in Santa Rosa averages a daytime high of 30.9°C and an overnight low of 23.9°C.
September runs -0.3°C compared to Santa Rosa's annual average high of 31.2°C, ranking #6 of 12 months by warmth.
Plan for daytime highs near 30.9°C and cooler evenings around 23.9°C.