Weather is probably a major factor when you plan your trip to Cowansville, and keep 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 temp of 64°F, while the coldest months are January and February with an average of 22°F. The snowiest months in Cowansville are January, December, March, and February, with each month seeing an average of 12 inches of snowfall.