January in Namsos is the snowiest, the windiest, and the coldest month of the year. In January, the weather in Namsos is typically freezing. Average daily high temperature in January is about zero. On average, Namsos has 9 rainy, 9 cloudy, 5 sunny, 5 partly cloudy, and 3 snowy days in January. The rains are usually heavy. January as well as February, March, April, and May is considered the most uncomfortable time to visit Namsos.