In May, Portland typically sees daytime highs of 17.8°C and overnight lows around 6.8°C. Compared to the annual average high of 12.6°C, May runs +5.3°C.
May in Portland averages a daytime high of 17.8°C and an overnight low of 6.8°C.
May runs +5.3°C compared to Portland's annual average high of 12.6°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 17.8°C and cooler evenings around 6.8°C.