In September, Sioux City typically sees daytime highs of 24.8°C and overnight lows around 10.5°C. Compared to the annual average high of 15.8°C, September runs +9.1°C.
September in Sioux City averages a daytime high of 24.8°C and an overnight low of 10.5°C.
September runs +9.1°C compared to Sioux City's annual average high of 15.8°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 24.8°C and cooler evenings around 10.5°C.