Mendota Freeze Contest
On Wednesday, December 1st, Clean Lakes Alliance will kick off its 10th 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.
When will Lake Mendota freeze?
- 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.
- Read more about the 2020-2021 season freeze declaration.
Our 2020-2021 winner!
Temperatures below the freezing mark and plenty of cloud cover, combined with cold water helped Lake Mendota officially freeze on Sunday, January 3rd, 2021, as declared by the Wisconsin State Climatology Office. Lake Mendota, the largest lake in the Yahara Watershed, froze 27 days shy of January 30th – which is the latest date that ice-on has ever been declared (1/30/1932).
The Wisconsin State Climatology Office requires ice to hold for a period of 24 hours before a lake can officially be declared frozen over. The January 3rd freeze date is nine days before last year’s freeze date of January 12th. The median freeze date for Lake Mendota is December 20th.
The January 3rd, 2021 freeze date marks the conclusion of Clean Lakes Alliance’s ninth annual Mendota Freeze Contest. Weather watchers and ice experts of all ages were asked to guess the official ice-on date for Lake Mendota. The Mendota Freeze Contest calls attention to the year-round importance of our lakes on our local quality of life.
Of the more than 1800 people to enter the contest, over 50 guessed Lake Mendota would freeze on January 3rd, 2021. Randomly selected from those to guess the correct date was Wayne J. Hanson of Poynette. He received a $1,000 gift card courtesy of Lands’ End as the grand prize. Hanson says he will likely use his winnings to buy a Lands’ End blanket or two for his wife, and an ice fishing jacket for himself. This was the first time Hanson entered the Mendota Freeze Contest, which he saw advertised on Facebook. He said his January 3rd date was just a lucky guess!
A look back at the 2019-2020 season
A warm snap near the end of December kept Lake Mendota open well past its median freeze date of December 20th, and even through the end of 2019. The largest lake in the Yahara Watershed wasn’t officially declared frozen over until January 12th, 2020.
The mid-January ice-on day, which is declared every year by the Wisconsin State Climatology Office, was only 18 days shy of the latest freeze date on record – January 30, 1932. The Wisconsin State Climatology Office declared Lake Mendota “open” again on March 22, 2020. The 70-day freeze duration was well shy of the median freeze duration of 104 days.
Only one guess per individual. Multiple entries will be automatically disqualified. Official rules and regulations can be found here.