In May, Wheaton typically sees daytime highs of 21.6°C and overnight lows around 8.8°C. Compared to the annual average high of 14.7°C, May runs +6.8°C.
May in Wheaton averages a daytime high of 21.6°C and an overnight low of 8.8°C.
May runs +6.8°C compared to Wheaton's annual average high of 14.7°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 21.6°C and cooler evenings around 8.8°C.