In May, Boulder typically sees daytime highs of 17.2°C and overnight lows around 2.3°C. Compared to the annual average high of 13.6°C, May runs +3.5°C.
May in Boulder averages a daytime high of 17.2°C and an overnight low of 2.3°C.
May runs +3.5°C compared to Boulder's annual average high of 13.6°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 17.2°C and cooler evenings around 2.3°C.