Duration of Ice on Lake Mendota, approx 5 x 8 x 30" 
Embroidery on silk

View the ice-over and ice-out dates for Lake Mendota back to 1852 here. Lake Mendota has lost an average of 29 days of ice cover during this time period.

The impacts of reduced ice cover are ecologically significant for lakes and their aquatic species. Ice cover regulates lake temperatures, dissolved oxygen levels, light penetration, and many other ecological parameters that govern growth and reproduction of species and interspecies relationships. Because ice cover reduces wintertime evaporation, it helps to maintain a lake’s water level. A lack of ice cover means that winter winds can make contact with lake waters, disturbing fish nesting sites, and impacting the ways lakes stratify, or form layers of water ordered along a temperature gradient. No ice cover also means no snow cover, allowing sunlight to penetrate the water and increase its temperature. In turn, warmer water temperatures may make the Madison lakes more hospitable to non-native species. (From the website Climate Wisconsin.org.)