Average Temperature in Seattle by Month

Seattle has a Mediterranean climate, classified as Csb in the Köppen system. The warmest month is July with an average high of 25°C, while the coldest month is January with lows dropping to 2°C. The annual temperature range of 23°C reflects moderate seasonal variation.

The driest month is August with only 5 rain days and 34mm of precipitation. For travellers, August through to the following month typically offers the best balance of warm temperatures and dry conditions. Average humidity ranges from 65% to 65% throughout the year.