In May, Rapid City typically sees daytime highs of 20.1°C and overnight lows around 5.8°C. Compared to the annual average high of 15.6°C, May runs +4.5°C.
May in Rapid City averages a daytime high of 20.1°C and an overnight low of 5.8°C.
May runs +4.5°C compared to Rapid City's annual average high of 15.6°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 20.1°C and cooler evenings around 5.8°C.