December in Bielsko-Biala is the windiest month of the year. In December, the weather in Bielsko-Biala is typically cold. Average daily high temperature in December is about 1 degree above zero. On average, Bielsko-Biala has 10 cloudy, 8 rainy, 5 snowy, 4 sunny, and 4 partly cloudy days in December. The rains are usually moderate. December as well as February, March, April, and May is considered the most uncomfortable time to visit Bielsko-Biala.