December in Russian Mission is the snowiest and the windiest month of the year. In December, the weather in Russian Mission is typically freezing. Average daily high temperature in December is about 10 degrees below zero. On average, Russian Mission has 16 snowy, 11 cloudy, and 4 sunny days in December. The snowfalls are usually moderate. December as well as January, February, March, and April is considered the most uncomfortable time to visit Russian Mission.