Great Lakes Ice Coverage is Shrinking

While there is significant year-to-year variability in ice coverage, trends show that annual maximum ice coverage on each of the Great Lakes has declined over time. Across all the Great Lakes, the annual maximum ice cover is, on average, 22% lower than it was a half-century ago. Furthermore, ice coverage is becoming less reliable, with more frequent years of extremely low ice coverage (like this year).

The decline in lake ice coverage is driven by warming air and water temperatures due to climate change. The lake ice season is also contracting in many cases, with lakes now tending to freeze over later and thaw out sooner. 

Not only are they vital sources of drinking water and irrigation for the country as a whole, cultural and recreational practices connected to the lakes and lake ice are deeply rooted in the surrounding communities. From ice fishing to skating, traditional ceremonial practice and the use of ice roads, the endurance of a rich variety of historical and cultural connections with Great Lakes ice is at risk of slipping through our fingers as a result of climate change.