MADISON, Wis. — Earlier this month Madison hosted the 14th annual Frozen Assets Festival, an event put on by Clean Lakes Alliance to celebrate the city’s winter connection to its lakes. “When our lakes are frozen, they are truly our greatest asset,” says James Tye, the nonprofit’s executive director and founder.
Madison sits on an isthmus between Lake Mendota and Lake Monona; the narrow strip of land means the lakes are woven into daily life. In winter the waters become venues for ice fishing, skating, ice sailing and snowshoeing. Historically the lakes supported commercial activity too: “There’s a long history of ice harvesting in this region,” says Hilary Dugan, a limnologist at the University of Wisconsin–Madison. Blocks of ice were cut from the lakes through much of the 20th century.
The community has even tracked freeze dates for more than a century, and the city runs a contest where people guess the day Lake Mendota will freeze. That date, on average, is shifting later. “We’ve actually lost about a month of lake ice duration here in Madison,” Dugan says. She adds that ice that does form is less reliably safe: “Traditionally, these were lakes that froze really safely every winter. And that’s becoming less — we’re less confident in that, going into the future.”
Fluctuating winter temperatures tied to climate change make ice conditions more unpredictable. In 2024 organizers canceled the on-ice portion of Frozen Assets because it was too warm and the ice showed worrying signs. This year, however, Lake Mendota built up more than a foot of ice by early February, enough to host the festival’s more than 1,000 attendees.
The event offered kite flying, skydiving demonstrations, ice hockey and the festival’s unique 5K run held entirely on ice. Scientists from the UW–Madison Center for Limnology ran demonstrations showing attendees how to measure ice thickness and discussed lake ecology and changing winter conditions. Traditional Indigenous winter games were also on display: Ho-Chunk Nation members taught snow snake, a sport where handcrafted wooden sticks are slid down a trench of packed snow for distance.
Scenes from the festival captured families and competitors on the ice, runners warming up for the 5K, kite enthusiasts launching colorful fish and owl kites, and anglers tending holes on Monona Bay. Participants measured ice with augers and ice skimmers, children played among kites, and a skydiver glided over the frozen surface above the city.
Organizers and researchers use the festival both to celebrate winter recreation and to highlight how climate trends are changing local ice regimes. Even as people embraced the day on Lake Mendota, the event underscored a growing uncertainty about how long and how safely the lakes will freeze in years to come.
(Photo captions: People gather on Lake Mendota near an inflatable Statue of Liberty crown and torch at the Winter Carnival; Hilary Dugan drills a hole with an electric auger; competitors run a 5K on ice; runners warm up; children measure ice thickness with a researcher; Ho-Chunk Nation members teach snow snake; skaters use the Edgewater Hotel rink; colorful kites fill the sky; a skydiver glides above Lake Mendota; anglers ice fish on Monona Bay. All photos by Kayla Wolf for NPR.)