The most pleasant months of the year for the 99034 zip code are September, June and July. In the 99034 zip code, there are 4 comfortable months with high temperatures in the range of 70-85°. August is the hottest month for the 99034 zip code with an average high temperature of 83.7°, which ranks it as warmer than most places in Washington. December is the snowiest month in the 99034 zip code with 14.1 inches of snow, and 6 months of the year have significant snowfall. Days with noticeable humidity are rare throughout the year.