September in Umiujaq is the rainiest month of the year. In September, the weather in Umiujaq is typically cold. Average daily high temperature in September is about 8 degrees above zero. On average, Umiujaq has 18 rainy, 6 partly cloudy, 4 cloudy, and 2 sunny days in September. The rains are usually heavy. September as well as January, February, March, and June is considered the most uncomfortable time to visit Umiujaq.