Disclaimer:

Dates listed below are for informational and non-scientific purposes only and should be used as such given uncertainty in the historical record of observation and/or source. There are several ancecdotal articles from the Burlington Free Press and other local papers during the 1800s citing "closure" dates and these were recorded in original Burlington, VT climate record books housed locally at NWS Burlington. These are referenced as closed due to a variety of reasons, including 1) cessation of commercial shipping traffic or 2) full ice coverage on the broad lake from Burlington directly west/northwest to Port Kent, NY as observed from local reports or observations from the Battery Park overlook. There are other lists of closing dates in the historical record, for example from Shoreham, VT to Old Fort Ticonderoga among others. Given this information, it is impossible to determine whether the lake was ever 100% ice covered during many older years listed as "closed". In recent years (2009-present) NWS Burlington has archived satellite data imagery at 250m resolution from NASA's Terra and Aqua polar orbiting satellites to determine approximate ice coverage on the lake for recreational planning purposes (see our Lake Champlain Ice Coverage section at: https://www.weather.gov/btv/recreation). It is through this imagery that a subjective determination of approximate ice coverage is made, and whether the lake is iced over. If "iced over" conditions are observed it is with the full realization that small stretches, or gaps of open water may still exist on portions of the lake which are too small to be observed by the satellite data.

Data from 1816-1871 recorded c. 1910 in the U.S. Weather Bureau Climatological Record Book for Burlington, VT, and cited from a older Burlington Free Press clipping (Data sources unknown).

Data from 1872-1886 recorded by Charles E. Allen.

Data from 1886-1906 recorded by cooperative weather observer Mr. W. B. Gates.

Data from 1906 onward recorded by either the U.S. Weather Bureau or National Weather Service.