In December, the weather in Zheleznogorsk-Ilimsky is typically freezing. Average daily high temperature in December is about 17 degrees below zero. On average, Zheleznogorsk-Ilimsky has 18 cloudy, 10 snowy, and 3 sunny days in December. The snowfalls are usually light. December as well as January, February, April, and May is considered the most uncomfortable time to visit Zheleznogorsk-Ilimsky.