The ice officially melted on Douglas Lake on Saturday, March 16, setting another record for this mild winter.
It comes after the latest ice-in ever recorded — Jan. 6 — making the 2023-2024 season the shortest Douglas Lake ice cover recorded at the University of Michigan Biological Station: just 70 days.
UMBS has tracked the lake’s ice cover for more than 90 years. Researchers have held an annual contest among themselves to guess the correct date since 1988.
But just like other regional traditions such as sturgeon fishing or maple tree tapping, warming climates and El Niño winds made this year especially challenging.
The ice-out date is declared when 75 percent of ice cover disappears from South Fishtail Bay, the deepest part of the south end of the lake.
Douglas Lake, and the greater Pellston area are typically outliers in climate data.
Often regarded as "Michigan's icebox," the Village of Pellston sees below average temperatures due to its position in a sand basin between two ranges of hills near the Maple River.
It holds the state's record-low temperature of -53 degrees Fahrenheit, set in 1933.
Adam Schubel
University of Michigan Biological Station, Pellston
But biologist Adam Schubel said Douglas Lake was not excluded from the “double-whammy” of climate change and El Nino winds from the Pacific Ocean.
“The trend is not as strong on this lake and in this bay in particular, as it is on the Great Lakes, for example,” Schubel said. “But we expect that to change over time. We expect ice cover to be shorter and shorter as the climate continues to change.”
Schubel said when he returned from a vacation in mid-March, he knew he’d need to change the deadline for his team to guess the ice-out date.
Three days before the ice melted he measured its thickness at 5.5 inches. Using the data, he was able to correctly predict the ice would be melted by March 16. His colleague, biologist John Lenters, also guessed correctly.
“Different scientists and participants tend to be a little secretive about their methods,” Schubel said. “We both guessed the same day. So we both shared the win!”
Lenters, a senior research specialist at UMBS, studies changing winters in Michigan. He said this year’s El Niño — caused by above-average sea surface temperatures in the tropical Pacific Ocean — was amplified.
“El Niño was a huge contributor to this winter,” he said. “But it was even worse than previous El Niños - that's the fingerprint of climate change in that.
“I think the warm winter kind of lulls people into thinking there's going to be a warm spring. But when we get an El Niño like this and then it weakens - we return to more normal spring-like conditions.”
The researchers said they hope to compile more regional inland lakes into their data.
More data, they say, will help build a better understanding of how climate change is affecting the Great Lakes region.
