May in Bangor is the rainiest month of the year. In May, the weather in Bangor is typically warm. Average daily high temperature in May is about 15 degrees above zero. On average, Bangor has 16 rainy, 6 cloudy, 5 sunny, and 4 partly cloudy days in May. The rains are usually heavy. May as well as March, April, and November is considered the most uncomfortable time to visit Bangor.