In May, Portland typically sees daytime highs of 19.6°C and overnight lows around 7.2°C. Compared to the annual average high of 16.7°C, May runs +3.0°C.
May in Portland averages a daytime high of 19.6°C and an overnight low of 7.2°C.
May runs +3.0°C compared to Portland's annual average high of 16.7°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 19.6°C and cooler evenings around 7.2°C.