In December, the weather in Rostov-na-Donu is typically cold. Average daily high temperature in December is about 2 degrees above zero. On average, Rostov-na-Donu has 20 cloudy, 7 rainy, 3 sunny, and 1 snowy day in December. The rains are usually light. December as well as February and March is considered the most uncomfortable time to visit Rostov-na-Donu.