December in Bellingham is the snowiest, the windiest, and the coldest month of the year. In December, the weather in Bellingham is typically cold. Average daily high temperature in December is about 6 degrees above zero. On average, Bellingham has 16 rainy, 5 sunny, 5 cloudy, 4 partly cloudy, and 1 snowy day in December. The rains are usually heavy. December as well as January, February, March, and April is considered the most uncomfortable time to visit Bellingham.