December in Northeim is the rainiest and the windiest month of the year. In December, the weather in Northeim is typically cold. Average daily high temperature in December is about 3 degrees above zero. On average, Northeim has 21 rainy, 8 cloudy, and 2 sunny 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 Northeim.