December in Mont St Michel is the rainiest and the windiest month of the year. In December, the weather in Mont St Michel is typically cold. Average daily high temperature in December is about 9 degrees above zero. On average, Mont St Michel has 19 rainy, 7 partly cloudy, 4 sunny, and 1 cloudy day in December. The rains are usually heavy. December as well as January, February, March, and April is considered the most uncomfortable time to visit Mont St Michel.