April in Duluth is the windiest month of the year. In April, the weather in Duluth is typically cold. Average daily high temperature in April is about 7 degrees above zero. On average, Duluth has 13 cloudy, 9 rainy, 5 sunny, and 3 partly cloudy days in April. The rains are usually heavy. April as well as January, March, and November is considered the most uncomfortable time to visit Duluth.