In August, Seattle typically sees daytime highs of 23.5°C and overnight lows around 12.7°C. Compared to the annual average high of 15.2°C, August runs +8.3°C.
August in Seattle averages a daytime high of 23.5°C and an overnight low of 12.7°C.
August runs +8.3°C compared to Seattle's annual average high of 15.2°C, ranking #2 of 12 months by warmth.
Plan for daytime highs near 23.5°C and cooler evenings around 12.7°C.