December in Grandfontaine is the windiest month of the year. In December, the weather in Grandfontaine is typically cold. Average daily high temperature in December is about 3 degrees above zero. On average, Grandfontaine has 23 rainy, 5 cloudy, and 3 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 Grandfontaine.