May in Bangor is the sunniest month of the year. In May, the weather in Bangor is typically warm. Average daily high temperature in May is about 13 degrees above zero. On average, Bangor has 18 rainy, 6 sunny, 5 partly cloudy, and 2 cloudy days in May. The rains are usually moderate. May as well as January, February, March, and April is considered the most uncomfortable time to visit Bangor.