January in Rostov-na-Donu is the snowiest, the cloudiest, and the most freezing month of the year. In January, the weather in Rostov-na-Donu is typically freezing. Average daily high temperature in January is about 2 degrees below zero. On average, Rostov-na-Donu has 19 cloudy, 10 snowy, and 2 sunny days in January. The snowfalls are usually moderate.