December in Rostock is the rainiest, the windiest, and the cloudiest month of the year. In December, the weather in Rostock is typically cold. Average daily high temperature in December is about 4 degrees above zero. On average, Rostock has 20 rainy, 10 cloudy, and 1 sunny day in December. The rains are usually moderate. December as well as January, February, October, and November is considered the most uncomfortable time to visit Rostock.