May in Mo i Rana is the rainiest month of the year. In May, the weather in Mo i Rana is typically cold. Average daily high temperature in May is about 5 degrees above zero. On average, Mo i Rana has 25 rainy, 4 sunny, and 2 cloudy days in May. The rains are usually heavy. May as well as June, July, August, and September is considered the most uncomfortable time to visit Mo i Rana.