January in Omsk is the most freezing month of the year. In January, the weather in Omsk is typically freezing. Average daily high temperature in January is about 15 degrees below zero. On average, Omsk has 26 cloudy, 3 sunny, and 2 snowy days in January. The snowfalls are usually light. January as well as February and December is considered the most uncomfortable time to visit Omsk.