seattle weather averages by month
Seattle: Annual Weather Averages. July is the hottest month in Seattle with an average temperature of 18Â°C (64Â°F) and the coldest is January at 5Â°C (41Â°F) with the most daily sunshine hours at 10 in July. The wettest month is December with an average of 150mm of rain.
The highest monthly average temperature in Seattle for July is 64 degrees. The lowest monthly average temperature in Seattle for December is 42 degrees. The most monthly precipitation in Seattle occurs in January with 0 inches. The air quality index in Seattle is 1% better than the national average. The pollution index in Seattle is 78% better than the national average.