When will Lake Mendota freeze?
On December 1st, Clean Lakes Alliance kicked off its 11th annual Mendota Freeze Contest. Calling on weather watchers and ice experts of all ages, the contest asks people to guess the official ice-on date for Lake Mendota. Of the nearly 1,600 people to enter the contest, 33 people guessed Lake Mendota would freeze on December 25th. Our winner, Laura Graham of Madison, was randomly selected from those who guessed the correct date. Graham will receive a $1,000 gift card courtesy of Lands’ End as the grand prize.
Freeze statistics for Lake Mendota
- For insight into the Wisconsin State Climatology Office, which declares the lakes frozen each year, read more about lake ice records from Wisconsin State Climatology Office
- The Wisconsin State Climatology Office makes the official determination as to whether the lake is frozen. The climatologists use the same guidelines they have used for decades. This allows for a continuity in data collection. Read more: Determining ice cover on Madison’s lakes.
- For statistics about determining the freeze date and the Madison ice record, see History of freezing and thawing of Lake Mendota and Madison lakes ice summary.
- To test your knowledge of our lakes in the winter, take the frozen lakes quiz.
A look back at the 2022-23 season
For the 11th year in a row, Clean Lakes Alliance held its annual Mendota Freeze Contest, asking people to make a guess as to when the lake would officially freeze. Frigid air temperatures, combined with cold water and low winds, helped Lake Mendota officially freeze on December 25th, 2022. The declaration came from the Wisconsin State Climatology Office. Lake Mendota, the largest lake in the Yahara Watershed, froze five days after December 20th. December 20th is the median ice-on date for the largest lake in the Yahara River Watershed. The Christmas Day freeze date is over a month shy of January 30th – which is the latest date that ice-on has ever been declared (1/30/1932).
The ice must hold for 24 hours before the Wisconsin State Climatology Office can declare the lake frozen. The December 25th freeze date is almost two weeks earlier than last year’s freeze date of January 7th. For statistics about determining the freeze date and the Madison ice record, see History of freezing and thawing of Lake Mendota and Madison lakes ice summary.
Only one guess per individual. Multiple entries will be automatically disqualified. Official rules and regulations can be found here.