75 on Tuesday, an ice-free lake, little snow: Climate change blunts winter in Chicago
Sean McGuire says climate played a significant role in where he chose to live after college.
After living in California, where wildfires and landslides have increased, and then attending college in New Orleans only a few years after Hurricane Katrina devastated the Gulf Coast in 2005, he was looking for an area better insulated from natural disasters.
“I really wanted to live in a region which I felt like, long term, had a lot of climate resilience,” he said. “And so I was always kind of interested in the Midwest.”
More than a decade later, the Humboldt Park resident said he has noticed significant changes in winter weather patterns, which he says have been an unexpected adjustment.
“Being here for 12 years you can definitely see that winters have changed. They’ve become shorter but sometimes more severe at times,” McGuire said. “I guess it makes me question my thesis of climate resilience; there’s really no region that’s completely immune.”
As meteorological winter comes to a close Thursday, temperatures are forecast to reach the mid-70s Tuesday, snowfall is more than 50% below average in Chicago, and ice coverage for the Great Lakes is in single digits.
While some may welcome these changing weather patterns, they also bring ecological concerns like the expansion of non-native species.
On Sunday, sunny weather drew crowds hauling blankets, books and picnics to the concrete steps along Lake Michigan near Belmont Harbor. As temperatures crept into the high 50s, it looked like a weekend in June, with scores of people walking dogs and roller-skating along the bike path. Several men jogged by shirtless.
“This is crazy,” a woman said as her group tried to cut through a constant stream of bikers and pedestrians going the opposite direction.
A few scattered patches of snow on the grass were the only evidence of the cold temperatures and snow that blew through the area Friday.
“Unfortunately or fortunately, however you look at it … it moved on rather quickly,” said Kevin Birk, a meteorologist for the National Weather Service in Chicago.
According to Trent Ford, the state climatologist, all four seasons have seen warmer temperatures because of human-driven climate change, but winter temperatures have increased at a much faster rate than all other seasons.
“Winter warming is probably the most substantial trend that we can see over the last 100 years as far as how our climate has changed, and is also strongly tied to sort of the global warming forcing,” Ford said.
Tuesday will be the hottest day this month, as temperatures could reach 75 and could break a record for that date set in 1976, Birk said.
More coverage: Chicago’s February is the warmest so far in nearly 150 years.
Last year was the warmest year on record globally, and last month was the warmest January on record, according to the National Oceanic and Atmospheric Administration.
McGuire said he became interested in climate resilience after seeing the effects of Hurricane Katrina and living in New Orleans when Hurricane Gustav hit in 2008.
When he first moved to Chicago, McGuire said he checked the U.S. Department of Agriculture’s Plant Hardiness Zone Map, which provides information about the average annual minimum winter temperature in specific geographical areas, to determine which plants would thrive in his backyard garden.
He said he was not surprised to learn the USDA released a new map in 2023 showing Chicago’s climate zone had changed to reflect the warming temperatures.
“There’s direct empirical evidence that things are changing that way, but you definitely see it every single year,” McGuire said. “It’s a fine science of when you plant your first plants in your backyard, and I’m looking around and it looks like a good time to start right now.”
A crucial role
Bryan Mroczka, a physical scientist with the Great Lakes Environmental Research Laboratory, said that compared with other areas of the continent, the Great Lakes region is experiencing some of the most significant rates of winter warming.
Mroczka said the average peak ice coverage for the Great Lakes is between 40% and 45%, but regional weather patterns have caused ice formation to significantly decline over the past 50 years.
According to NOAA, the Great Lakes had only 7.4% ice coverage on Saturday.
“We’ve seen, on average, a 5% decrease in ice on the lakes per decade. So put that in perspective, that’s about on average, 25% less ice on the Great Lakes since the early ’70s,” Mroczka said.
While the region has experienced brief periods of below-freezing temperatures, Mroczka said prolonged cold air is needed for ice formation, and the fluctuating temperatures in recent years due to a warming climate are making it challenging for this geological process to occur.
Alongside the gradual warming trend in the Northern Hemisphere, NOAA said an El Niño year started in June. The El Niño phenomenon, a period characterized by unusually warm sea surface temperatures in the central and eastern Pacific Ocean, occurs every two to seven years and significantly influences global weather patterns.
Alexander Gottlieb, a graduate student at Dartmouth who co-authored a recent study of the human influence on snowfall decline in the Northern Hemisphere, said El Niño events are reorganizing atmospheric pressure, which is contributing to warmer winters globally. However, Gottlieb said this trend can be explained by a combination of human-caused global warming and natural variability.
In addition to a lack of ice coverage on the Great Lakes, Gottlieb said the warming temperatures are causing declines in snowfall, particularly in the Midwest due to the increased likelihood of rain instead of snow.
Snowfall in Chicago has been declining over the past few years, with numbers well below the weather service’s 38.4-inch average. During the 2022-23 season, Chicago saw 20.2 inches of snow recorded at O’Hare International Airport, the city’s official recording site. So far, the city has only seen 18.5 inches of snow this winter, according to the weather service’s latest data.
In regions like the Midwest, which experience precipitation year-round, the impact of diminished snowpack is less pronounced, according to Gottlieb. However, he said snow plays a crucial role in protecting soil from freezing during the winter months, and without this protective barrier, some regions face heightened risk of midwinter flooding.
Tuesday will see thunderstorms pass through the area, so the possibility of minor flooding in the city is “not out of the question,” according to Kirk, the meteorologist.
“It’s almost like we’re ahead a month, more like late March, with the warm conditions we have here,” he said. “So (it’s) kind of a spring storm system coming across.”
The rain will bring in a cold front, causing temperatures to drop into the 30s Wednesday. But this cold spell will also likely be brief, as highs are expected to rebound into the 60s by the weekend.
Health concerns
Ford said warmer winters in the Great Lakes region have also caused ecological shifts.
“What we’ve seen is an expansion of certain species of plants and animals that would otherwise, in a preindustrial climate, not have been able to thrive in the state,” Ford said. “On its face value, that may not be that big of a problem, but some of these plants and animals are quite competitive … and can really wreak havoc in native ecosystems.”
Still, some of the effects of warmer winters are more subtle. Ford said the changing climate caused by global warming patterns poses health concerns many may not be aware of.
For example, warmer winters contribute to the expansion of tick and mosquito populations, increasing the prevalence of tick-borne diseases like Rocky Mountain spotted fever and Lyme disease.
‘These things are everywhere’: Experts and Lyme disease patients warn of tick season
Gradual warming also poses other challenges.
Mroczka said ice coverage plays a pivotal role in preventing shoreline erosion and coastal flooding, which can damage infrastructure near the lakes.
“The ice is actually very protective of our shorelines. And we’ve certainly seen some significant issues during winters when the ice is lacking,” Mroczka said.
Still, warmer winters bring some benefits. From an economic perspective, Mroczka said the lack of ice on the lakes significantly benefits the shipping industry, serving as a huge economic driver.
“There are entities out there that are excited about the lack of ice, but there are a lot of negatives too, mostly because the ecosystem is designed for ice. And when it’s not there, there are problems. And so we’ll just have to certainly adapt if this trend continues.”
Ford said it is important to adapt to the changing climate but also assess ways to mitigate the effects of global warming, primarily by reducing greenhouse gas emissions.
Chicago homeowner McGuire said he hopes the changing climate does not alter Chicago winters forever.
“You know, to think of snow being something that might not be something my (future) kids can enjoy one day is just, it’s just really sad,” McGuire said. “It just feels like something that’s completely outside our control.”
