Interactive provides simple buttons that allow users to view the 10 longest seasons, the 10 shortest seasons and the overall trend. The records show significant year-to-year variability in the length of the ice-cover season, but there is a clear trend of fewer ice-cover days over time. In both lakes, the 10 longest ice cover winters were prior to 1905; the shortest ice cover seasons mainly fall in the last 20 years.

This data illustrates the important point that although there is significant year-to-year variability, there also is an unmistakable trend in these data. There also are pop-ups that give the actual dates of ice cover and melting for each year.

Data ends in 2010. Up-to-date data can be accessed from the WI climatology office: [link http://www.aos.wisc.edu/~sco/lakes/Mendota-ice.html 'Mendota'] and [link http://www.aos.wisc.edu/~sco/lakes/Monona-ice.html 'Monona'].

Comments from expert scientist: The resource provides a useful, easy-to-read historical record of ice cover for two well-known lakes in Madison, WI. The biological and limnological significance of changing ice cover on the lakes is explained accurately and at a level accessible to non-scientists. In each case, the science is accurate and accessible to anyone interested in understanding how climate change has affected Wisconsin.