December in Pullman is the snowiest and the coldest month of the year. In December, the weather in Pullman is typically cold. Average daily high temperature in December is about 1 degree above zero. On average, Pullman has 10 rainy, 6 snowy, 6 cloudy, 6 partly cloudy, and 3 sunny days in December. The rains are usually moderate. December as well as January, February, March, and April is considered the most uncomfortable time to visit Pullman.