December in Bern is the windiest month of the year. In December, the weather in Bern is typically cold. Average daily high temperature in December is about 4 degrees above zero. On average, Bern has 11 partly cloudy, 10 rainy, 9 sunny, and 1 cloudy day in December. The rains are usually moderate. December as well as January, February, March, and April is considered the most uncomfortable time to visit Bern.