In May, Seattle typically sees daytime highs of 18.1°C and overnight lows around 8.2°C. Compared to the annual average high of 15.2°C, May runs +2.9°C.
May in Seattle averages a daytime high of 18.1°C and an overnight low of 8.2°C.
May runs +2.9°C compared to Seattle's annual average high of 15.2°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 18.1°C and cooler evenings around 8.2°C.