In May, Sioux City typically sees daytime highs of 23.3°C and overnight lows around 9.1°C. Compared to the annual average high of 15.8°C, May runs +7.5°C.
May in Sioux City averages a daytime high of 23.3°C and an overnight low of 9.1°C.
May runs +7.5°C compared to Sioux City's annual average high of 15.8°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 23.3°C and cooler evenings around 9.1°C.