January in Hanover is the cloudiest and the coldest month of the year. In January, the weather in Hanover is typically cold. Average daily high temperature in January is about 3 degrees above zero. On average, Hanover has 15 cloudy, 13 rainy, and 3 sunny days in January. The rains are usually light. January as well as February, November, and December is considered the most uncomfortable time to visit Hanover.