In December, the weather in Bangor is typically freezing. Average daily high temperature in December is about 1 degree above zero. On average, Bangor has 10 sunny, 9 partly cloudy, 5 snowy, 4 cloudy, and 3 rainy days in December. The snowfalls are usually heavy. December as well as February, March, April, and October is considered the most uncomfortable time to visit Bangor.