In August, Portsmouth typically sees daytime highs of 30.1°C and overnight lows around 20.3°C. Compared to the annual average high of 20.6°C, August runs +9.5°C.
August in Portsmouth averages a daytime high of 30.1°C and an overnight low of 20.3°C.
August runs +9.5°C compared to Portsmouth's annual average high of 20.6°C, ranking #2 of 12 months by warmth.
Plan for daytime highs near 30.1°C and cooler evenings around 20.3°C.