The good old Minnesota winter is losing its bite

Minnesota winters just aren't what they used to be. And the numbers prove it.

Winters are warming across the country, but Minnesota is among the states where temperatures are rising even more dramatically. In fact, Minneapolis and Mankato, followed by Fargo, are among the top five spots in the country where those temperatures are rising the most, according to recent research published by Climate Central, a group of scientists and journalists who report on the changing climate.

"You just can't take cold or snow for granted, which sounds bizarre to say to a Minnesotan," said Twin Ciites meteorologist Paul Douglas. "The majority of our winters are trending milder, with less consistent snow. It's not your grandfather's winter … where you had snow on the ground consistently from late October through early April."

By Douglas' count, one in four winters over the past 20 years has been what he calls "an old-fashioned, butt-kicking Minnesotan winter." Instead, they've become increasingly erratic.

The warming trend may be good news for those who prefer to skip winter and go right to spring. But it can be tough sledding for those who celebrate it, and for the businesses that depend on cold and snow to get people out on skis, snowmobiles and the ice.

The warming trend is a mixed bag, with winners and losers, said Pete Boulay, climatologist with the Minnesota Department of Natural Resources (DNR). Pipes are less likely to freeze and fewer Minnesotans may have to plug in car engine-block heaters at night, he said. But it also may mean that pests like the Japanese beetle and emerald ash borer will survive winter, allowing for major attacks come summer.

Scientists are keeping a close eye on how these temperature changes will affect the environment and the state's ecosystems, possibly changing Minnesota as we know it.

Some changes that can be seen now are subtle, said Carrol Henderson, the DNR's nongame wildlife program supervisor. Some birds can now stay through the winter rather than migrate to warmer climates. Others sometimes migrate later and return earlier, he said. That could be a good or bad thing, depending on whether the insects they like to eat are available, he added.

"The red-tailed hawks that you see all along the highways can hunt in the grass more easily than if there was snow cover," Henderson said. "And yet there are some birds like the ruffed grouse in northern Minnesota that need the snow. They burrow into it to stay insulated at night from cold temperatures."

According to Climate Central, the winter warm-up trend is the most dramatic in the Northern Plains, Great Lakes and the Northeast.

In parts of Minnesota, Wisconsin and northern New England, winters have warmed an average of more than 1 degree every decade since 1970, the report said. Leading the list, the average temperature in Burlington, Vt., is 7 degrees warmer now than in 1970, followed by Mankato and Minneapolis, which are 6 degrees warmer. Average winter temperatures are 5.9 degrees warmer in Fargo and Waterloo, Iowa. Duluth registered 5.8 degrees warmer.

Winter in these areas are warming faster because cold areas and cold seasons warm faster than warm seasons and the warmer areas of the country, the report said.

In Minnesota, the more dramatic warming trend is tied to snow cover, Boulay said. Warmer temperatures mean snow doesn't stick around as long. "And without snow, it warms even faster," he added.

"The real change is that our extreme cold is missing," Boulay said. "We just don't get down to minus-20 degrees very often in the Twin Cities. And areas above St. Cloud don't get down to minus-30 as often."

The good news is that may make it more tolerable for some people to play outside, provided there's enough snow and lake ice to enjoy the winter sports.

But the upward trend in winter temps hasn't meant that every winter has been warmer, Boulay said. "It's been up and down," he said.

During the polar vortex in the winter of 2013-2014 winter, the Twin Cities chalked up more than 50 nights below zero, Boulay said. "Our average count [for below-zero nights] these days is 24," he said.

The polar vortex year also meant the Twin Cities saw more snow — 69.8 inches — that stuck around longer. In comparison, snow totals during the last three winters ranged from 32 to 36 inches — less than the 54.4 inches that was the normal from 1981-2010, Boulay said.

Less snow means drivers aren't sliding on slick roads as much, he said. It also means less sand and salt have to go on roads, saving money for state and local governments while reducing salt runoff into the environment, Boulay said.

On the flip side, Minnesota may see more winter rains that change into ice storms, Douglas said.

In a strange way, warmer winters could be a boon for the state, attracting people who normally would want to avoid frigid temperatures.

"For people who lived in mortal fear of winter, they will realize gradually that most our winters just aren't that bad," Douglas said.

Mary Lynn Smith • 612-673-4788