In May, Washington typically sees daytime highs of 13.6°C and overnight lows around 5.8°C. Compared to the annual average high of 11.4°C, May runs +2.2°C.
May in Washington averages a daytime high of 13.6°C and an overnight low of 5.8°C.
May runs +2.2°C compared to Washington's annual average high of 11.4°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 13.6°C and cooler evenings around 5.8°C.