Taking the local weather in Mont-Saint-Michel into account can help you maximise your time at the pool during your trip. The hottest months are usually July and August, with an average temperature of 16°C, while the coldest months are January and February, with an average of -9°C. The snowiest months in Mont-Saint-Michel are January, November, December and February, with each month seeing an average of 23 cm of snowfall.