December in Karlovy Vary is the windiest month of the year. In December, the weather in Karlovy Vary is typically cold. Average daily high temperature in December is about 1 degree above zero. On average, Karlovy Vary has 15 rainy, 7 snowy, 6 cloudy, 2 sunny, and 1 partly cloudy day in December. The rains are usually light. December as well as March, April, May, and November is considered the most uncomfortable time to visit Karlovy Vary.