In December, the weather in Kosmonosy is typically cold. Average daily high temperature in December is about 3 degrees above zero. On average, Kosmonosy has 16 cloudy, 7 rainy, 4 partly cloudy, 3 sunny, and 1 snowy day in December. The rains are usually light. December as well as January, February, and November is considered the most uncomfortable time to visit Kosmonosy.