December in Koscierzyna is the windiest month of the year. In December, the weather in Koscierzyna is typically cold. Average daily high temperature in December is about 1 degree above zero. On average, Koscierzyna has 14 rainy, 12 cloudy, 3 snowy, and 2 sunny days in December. The rains are usually moderate. December as well as February, March, October, and November is considered the most uncomfortable time to visit Koscierzyna.