January in Sejdisfjordur is the snowiest month of the year. In January, the weather in Sejdisfjordur is typically freezing. Average daily high temperature in January is about zero. On average, Sejdisfjordur has 9 cloudy, 9 partly cloudy, 7 snowy, 3 rainy, and 3 sunny days in January. The snowfalls are usually heavy.