Related Topics

Key

  ice out before March 25
  ice out March 25 to March 31
  ice out April 1 to April 7
  ice out April 8 to April 14
  ice out April 15 to April 21
  ice out April 22 to 28
  ice out April 29 to May 5
  ice out May 6 to May 12
  ice out after May 12
 

 

More Maps

Yearly Lake Ice Out Maps:

Median Lake Ice Out Map Earliest Lake Ice Out Map Latest Lake Ice Out Map

 

Notes

The map at left depicts historical median lake ice out dates using data archived by the DNR and the MPCA. Median is defined as the date where one half of the ice out dates were earlier, and one half of the ice out dates were later, than the presented date. To achieve lake-to-lake consistency, only 1950 - present dates were used to calculate the median. A marker is created for those lakes with ice out data whose period of record spans 20 or more years.

Hovering over the marker will cause the lake name and the median ice out date to be displayed. Clicking on the marker will produce an information window containing lake name, ice out summary statistics, and a link for obtaining all available historical ice out dates for the lake.

The map at left depicts the earliest lake ice out dates found in data archived by the DNR and the MPCA. A marker is created for those lakes with ice out data whose period of record spans 20 or more years.

Hovering over the marker will cause the lake name and the earliest ice out date to be displayed. Clicking on the marker will produce an information window containing lake name, ice out summary statistics, and a link for obtaining all available historical ice out dates for the lake.

The map at left depicts the latest lake ice out dates found in data archived by the DNR and the MPCA. A marker is created for those lakes with ice out data whose period of record spans 20 or more years.

Hovering over the marker will cause the lake name and the latest ice out date to be displayed. Clicking on the marker will produce an information window containing lake name, ice out summary statistics, and a link for obtaining all available historical ice out dates for the lake.

The map at left depicts lake ice out date reports received by the DNR and the MPCA for  . Hovering over the marker will cause the lake name and the ice out date to be displayed. Clicking on the marker will produce an information window containing lake name, ice out date, ice out summary statistics, and a link for obtaining all available historical ice out dates for the lake.

Definition of Lake Ice Out

The definition of lake ice-out varies from lake to lake, and individual to individual. For some, ice out occurs only when the lake is completely free of ice. For others, ice out is defined as the moment when navigation is possible from point A to point B. And yet for others, ice out is when 90 percent of the lake is ice free.

Due to the variable definitions of this rather subjective observation, the participating agencies attempt to contact the same individuals each year to maintain a consistent record for a particular lake.

Frequency of Updates

During the spring, lake ice out data are reported from a variety of sources, using a variety of communication channels. Every effort will be made to incorporate the data into the map as soon as possible. However, users of the map should be aware that map updates are not made in real-time.

 

For more information contact: climate@umn.edu