In May, Portsmouth typically sees daytime highs of 15.8°C and overnight lows around 7.6°C. Compared to the annual average high of 13.2°C, May runs +2.5°C.
May in Portsmouth averages a daytime high of 15.8°C and an overnight low of 7.6°C.
May runs +2.5°C compared to Portsmouth's annual average high of 13.2°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 15.8°C and cooler evenings around 7.6°C.