Weather is probably a major factor when you plan your trip to L'Ile-Perrot, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually July and August, with an average temperature of 19°C, while the coldest months are January and February, with an average of -6°C. The snowiest months in L'Ile-Perrot are January, February, December and March, with each month seeing an average of 60 cm of snowfall.