MADISON, Wis. – It's 48 degrees, and Ed Hopkins is looking for ice.
There's no shortage of it here along the shore of Maple Bluff, but a pair of eagles perched several hundred yards out hint at open water.
According to custom, the lake is considered frozen until you can row a boat the 2.5 miles from Picnic Point.
Hopkins peers through a set of Nikon binoculars.
“Most of it's ice,” he declares.
There may be some open water, though it could be rain pooled on top. The only way to know for sure is to go out and check.
For now, this lake is still officially iced in.
Hopkins, Wisconsin's assistant state climatologist, isn't just curious; he's carrying out tradition. Every winter and spring since the 1850s, observers have staked out Madison's lakes to determine when they freeze and thaw, adding to a vast data trove that offers a window into history.
The rules have been passed down by oral tradition.
Hopkins, the assistant state climatologist, has been doing the job for the past 15 years or so. He took over from Lyle Anderson, who started recording ice dates in the 1980s and who occasionally fills in for Hopkins.
Times have changed, but the methods haven't.
“Really it gets down to looking at the thing by eye,” Hopkins said. “While it's not rocket science, it does tell us if things are changing. You don't need a thermometer to do that.”
Wingra and Monona are considered frozen when they are half covered in ice. On average, Lake Monona opens March 30, about five days before Mendota, but ice out has happened as early as February and as late as May.
As the time gets closer, observations are a daily chore. Ice can form or disappear overnight. Rain and wind take their toll.
“Fog is a fantastic ice and snow eater,” Hopkins said.