The most pleasant months of the year for Lake Goodwin are August, July and September. In Lake Goodwin, there are 2 comfortable months with high temperatures in the range of 70-85°. August is the hottest month for Lake Goodwin with an average high temperature of 74.8°, which ranks it as cooler than most places in Washington. December is the snowiest month in Lake Goodwin with 1.7 inches of snow, and 4 months of the year have significant snowfall. There are few days during the summer when the humidity becomes unpleasant.