In May, Waterloo typically sees daytime highs of 18.4°C and overnight lows around 5.8°C. Compared to the annual average high of 11.9°C, May runs +6.6°C.
May in Waterloo averages a daytime high of 18.4°C and an overnight low of 5.8°C.
May runs +6.6°C compared to Waterloo's annual average high of 11.9°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 18.4°C and cooler evenings around 5.8°C.