December in Karlskrona is the rainiest and the windiest month of the year. In December, the weather in Karlskrona is typically cold. Average daily high temperature in December is about 4 degrees above zero. On average, Karlskrona has 22 rainy, 7 cloudy, and 2 sunny days in December. The rains are usually moderate. December as well as January, February, October, and November is considered the most uncomfortable time to visit Karlskrona.