January in Nyköping is the windiest, the cloudiest, and the most freezing month of the year. In January, the weather in Nyköping is typically freezing. Average daily high temperature in January is about zero. On average, Nyköping has 11 cloudy, 11 partly cloudy, 4 rainy, 3 sunny, and 2 snowy days in January. The rains are usually moderate. January as well as February, March, April, and May is considered the most uncomfortable time to visit Nyköping.