In May, Ontario typically sees daytime highs of 23.4°C and overnight lows around 9.3°C. Compared to the annual average high of 23.1°C, May runs +0.3°C.
May in Ontario averages a daytime high of 23.4°C and an overnight low of 9.3°C.
May runs +0.3°C compared to Ontario's annual average high of 23.1°C, ranking #6 of 12 months by warmth.
Plan for daytime highs near 23.4°C and cooler evenings around 9.3°C.