Winter Severity Index: So far, mostly mild
Winter Severity Index readings from across Minnesota confirm what most Northeastern Minnesota residents have sensed: Despite occasional cold stretches, this has been a fairly mild winter across the North.
WSI readings are compiled weekly by the Minnesota Department of Natural Resources, which uses the information primarily to judge how the state's deer herd is faring.
So far, readings across nearly all of the state are below 50 points, well within the "mild" range. Only two areas — one near International Falls and another inland in Cook County — have somewhat elevated readings.
Under the WSI ratings, one point is accumulated each day the temperature falls below zero, and another point is added for each day the snow is deeper than 15 inches.
"It's shaping up to be a mild winter," said Dave Olfelt, DNR regional wildlife manager at Grand Rapids. "The snow is a bigger deal than the cold (to deer). If you get a bunch of snow late in the winter when deer are hanging on, the snow can have a significant effect. But if I were a betting man, I'd say we're going to skate through."
Tom Rusch is DNR area wildlife manager at Tower. His area covers nine deer permit areas in northern St. Louis County.
"Currently, the WSI index ranges from 27 to 52 in the nine local deer permit areas," Rusch said. "These are all very low to mild indices for a Northeastern Minnesota winter and are almost identical to 2017."
Both Olfelt and Rusch say that this mild winter, on the heels of others, should mean another good fawn crop for the deer herd.
"Four consecutive mild to moderate winters is the prescription for northern forest deer population recovery from the severe winters of 2012-13 and 2013-14," Rusch said.
Snow depth in the Tower area exceeds the 15-inch WSI threshold only in far northern St. Louis County, Rusch said.