December in Hanover is the rainiest and the windiest month of the year. In December, the weather in Hanover is typically cold. Average daily high temperature in December is about 4 degrees above zero. On average, Hanover has 19 rainy, 9 cloudy, and 3 sunny days in December. The rains are usually light. December as well as January, February, and November is considered the most uncomfortable time to visit Hanover.