December in Grimsi is the windiest month of the year. In December, the weather in Grimsi is typically cold. Average daily high temperature in December is about 2 degrees above zero. On average, Grimsi has 26 rainy, 3 cloudy, and 2 sunny days in December. The rains are usually heavy. December as well as January, February, March, and April is considered the most uncomfortable time to visit Grimsi.