The Global Lake and River Ice Phenology database has seasonal freeze-up and breakup dates as well as other descriptive ice information for 865 lakes and rivers in twelve Northern Hemisphere countries. Sixty-six of these bodies of water have records longer than 50 years. In cooperation with the Lake Ice Analysis Group (LIAG) at the University of Wisconsin, Madison, NOAA@NSIDC has updated and added to the database, increasing the number of lakes and rivers it holds by over 13 percent.
A calendar correction was made to the Lake Suwa, Japan data. Records for Lake Suwa begin in 1443, but the earliest record is for Lake Constance in Germany, from year 874. Observations were made for religious, cultural, and practical, often transportation related, reasons. For more information and to obtain the data, see the Global Lake and River Ice Phenology Web site.