Nature Note – Lake Level

Falling leaves and falling lake levels are both a sign of autumn in the Champlain Valley. Photo by Rachel Ford James (

October is usually the month when Lake Champlain reaches its lowest levels.  The average lake level for October is 95.03 feet. Water evaporates throughout the heat of the summer. When plants are growing they transpire water through their leaves leaving less to go into rivers and streams. By October, evaporation has slowed as temperatures drop and day length shortens so less and less water leaves via that route. Meanwhile, plants are beginning to die back or drop their leaves for the winter so less water is lost to transpiration and the lake begins to fill-up again. Of course, tropical storms can affect our area as one did on September 30th and October 4th, dropping over five inches of rain in places. Events like this can temporarily offset the overall trend of falling lake levels as we approach Halloween.