December in Groningen is the windiest month of the year. In December, the weather in Groningen is typically cold. Average daily high temperature in December is about 6 degrees above zero. On average, Groningen has 19 rainy, 8 cloudy, 2 sunny, and 2 partly cloudy days in December. The rains are usually moderate. December as well as January, February, March, and October is considered the most uncomfortable time to visit Groningen.