In May, Sarnia typically sees daytime highs of 19.4°C and overnight lows around 7.4°C. Compared to the annual average high of 13.3°C, May runs +6.1°C.
May in Sarnia averages a daytime high of 19.4°C and an overnight low of 7.4°C.
May runs +6.1°C compared to Sarnia's annual average high of 13.3°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 19.4°C and cooler evenings around 7.4°C.