One of the most important things to know about the Mont-St-Michel weather is that it is directly related to the strong tides of the area.   The strongest and highest tides take place in March and September of each year.    (More information about travel to the area is available online at http://www.tripadvisor.com/Travel-g19... .)

The abbey of Mont-St-Michel is the site most often visited by travelers, so visitors should know that it is closed on certain days during the year, the 1st of January, 1st of May, and 25th of December.  While it is likely to be busy with tourists during the summer, it is also the only time to really fully experience the attractions of the area.  (More information about the other attractions and museums in the area, in addition to the abbey, is available online at http://www.tripadvisor.com/Travel-g19... ).  

In terms of events and activities taking place in the area, late summer is the best time to visit Mont-St-Michel.   More information about events in the area can be located online at http://www.tripadvisor.com/Travel-g19... .