December in Mirny is the most freezing month of the year. In December, the weather in Mirny is typically freezing. Average daily high temperature in December is about 27 degrees below zero. On average, Mirny has 27 cloudy, 2 snowy, and 2 sunny days in December. The snowfalls are usually light. December as well as January, February, March, and May is considered the most uncomfortable time to visit Mirny.