When Will Lake Mendota Freeze? Guessing Correctly Could Earn You a $1,000 Gift Card

MADISON, Wis. (WMDX) – Icicles have been spotted on Lake Mendota, and people who correctly guess when it’ll freeze could win a $1,000 gift card. 

The lake freezes every year, even if it’s only for a couple of weeks. People started monitoring it more than 170 years ago. 

The longest recorded freeze was the winter of 1880-81, which lasted 161 days. Last winter was our third-latest freeze date in recorded history; Lake Mendota was finally frozen on January 15. 

We have all this data because Mendota is one of the most studied lakes in the world, according to Clean Lakes Alliance founder James Tye. 

He said it’s easy to spot the impacts of climate change. 

“The 150-year average [of time the lake stays frozen] is about 102 days. But in the last five years, it’s only about 75 days,” Tye said. “Over 100 years ago, it would actually freeze in November, if you can believe it. And now we’re pushing late December, early January.”

They used to have an extremely Wisconsin way of determining what “frozen” meant on the lake. 

“They’d go up to one of the high points right, and then the other high point was over at Maple Bluff on the other side. And they decided that if you could get into a boat with a keg of beer and not get across the lake, it was frozen,” Tye said with a laugh. “Everything revolves back to boating and a little beverage or two, but that’s the official way, and that’s still how we track it. It’s not if the whole lake is frozen, it’s just frozen at its most major points, being Picnic Point, UW, and then over to Maple Bluff.”

The median freeze date is December 20. 

The Clean Lakes Alliance is holding its yearly freeze contest. You can guess when Lake Mendota will freeze, and whoever’s right will be entered into a drawing for a $1,000 gift card to Lands End.