January in Sonderborg is the snowiest, the cloudiest, and the coldest month of the year. In January, the weather in Sonderborg is typically cold. Average daily high temperature in January is about 3 degrees above zero. On average, Sonderborg has 10 cloudy, 9 rainy, 8 partly cloudy, 3 sunny, and 1 snowy day in January. The rains are usually moderate. January as well as February, March, April, and October is considered the most uncomfortable time to visit Sonderborg.