Take a look at the nighttime low temperatures from 2012. Always around 60 degrees even when it was hot during the day. 60 degrees is lower than most people would ever set an air conditioner. Start bringing that cool air inside as soon as the the day starts cooling down and while you sleep. Naturally Cool VT will help you do that!
Go to the page link below to see where this graph was taken from and see more weather information for Burlington http://weatherspark.com/history/29818/2012/Burlington-Vermont-United-States