January in Groningen is the coldest month of the year. In January, the weather in Groningen is typically cold. Average daily high temperature in January is about 4 degrees above zero. On average, Groningen has 20 rainy, 7 cloudy, 3 sunny, and 1 partly cloudy day in January. The rains are usually moderate. January as well as February, March, October, and November is considered the most uncomfortable time to visit Groningen.