In April, the weather in Sejdisfjordur is typically cold. Average daily high temperature in April is about 3 degrees above zero. On average, Sejdisfjordur has 11 cloudy, 6 partly cloudy, 5 rainy, 4 snowy, and 4 sunny days in April. The rains are usually heavy. April as well as May, June, July, and August is considered the most uncomfortable time to visit Sejdisfjordur.