January in Karlskrona is the snowiest, the cloudiest, and the coldest month of the year. In January, the weather in Karlskrona is typically cold. Average daily high temperature in January is about 2 degrees above zero. On average, Karlskrona has 15 rainy, 13 cloudy, 2 sunny, and 1 snowy day in January. The rains are usually light. January as well as February, October, November, and December is considered the most uncomfortable time to visit Karlskrona.