The long-term average for ice cover on the Great Lakes between the years 1973 and the present is 53%, although last winter coverage rose to 92%. Great Lakes ice is part and parcel of weather and the environment but also affects the economy including hydropower, commercial shipping and the fishing industry. There is a strong relationship between regional climate, water temperature, water movement and even spring plankton blooms. More information about Lake Superior and Great Lakes ice, including maps showing coverage, can be found below:
- National Oceanic and Atmospheric Administration Great Lakes Environmental Research site
- Great Lakes historical ice cover over time (1973 – to 2014)
- NOAA Great Lakes Environmental Research Laboratory.