by Across much of America and especially in the usually cold north, the country went through the winter months without, as it were, winter.
In the parka stronghold of Burlington, Vermont, and Portland, Maine, the thermometer never fell below zero. The state of Minnesota called the last three months “the lost winter”, warmer than the famous “year without winter” between 1877-1878. Michigan, where mosquitoes were biting in February, offered disaster loans to businesses hit by a lack of snow. The Great Lakes set records for low winter ice, with Erie and Ontario “essentially ice-free.”
For a wide swath of the country from Colorado to New Jersey, and from Texas to the Carolinas, spring leaves are coming three to four weeks earlier than the 1991-2020 average, according to the National Physiological Network, which tracks timing plants, insects. and other natural signs of the seasons.
“The long-term warming combined with El Nino conspired to make the U.S. winter not show up this year,” said Yale Climate Connections meteorologist Jeff Masters, who co-founded the private firm Weather Underground. Masters said he was bitten by a mosquito in Michigan this year, which he called crazy.
On Friday, the National Oceanic and Atmospheric Administration confirmed that the winter of 2023-2024 was the warmest in nearly 130 years of record keeping for the United States. The Lower 48 states averaged 37.6 degrees (3.1 degrees Celsius), which is 5.4 degrees (3 degrees Celsius) above average.
This is just the latest in a nightmare of broken national and global temperature records, which scientists say is mainly from human-caused climate change from the burning of coal, oil and gas.
And it was the warmest winter in the US by a wide margin. The past three months were 0.82 degrees (0.46 degrees Celsius) warmer than the previous record set eight years ago, which is “a good leap above the previous record,” said Karin Gleason, head of monitoring at Centers National Environmental Information NOAA.
Last month was only the third warmest February on record. But Iowa blew 2 degrees over its warmest February, and parts of Minnesota were 20 degrees warmer than average for the entire month of February, Gleason said.
On February 11, Great Lakes ice cover reached an all-time low in February of 2.7%.
A strong ridge of high pressure kept the eastern United States warm and dry, while California was still battered by atmospheric rivers, she said.
The European climate agency Copernicus said earlier this week that it was the warmest winter on earth, mainly due to climate change with an additional boost from the natural El Nino, which changes the weather around the world and provides extra warmth.
Over the past 45 years, winters have warmed faster in the United States than in the rest of the world, and winters in the Lower 48 states are now 2.2 degrees (1.2 degrees Celsius) warmer than in 1980, according to an analysis of NOAA data by The Associated. Press.
That’s likely because the land is warming faster than the ocean with much of the United States as land and most of the globe as ocean, Gleason said.
Although it is still getting warmer in the United States, since 2000 the rate of further warming has slowed slightly, NOAA data show. Winter weather expert Judah Cohen of Atmospheric Environmental Research, a commercial firm outside Boston, blames Arctic Amplification, which is how climate change has warmed the Arctic three to four times more than the rest of the world and it seems that weather patterns shift further south.
As the Arctic moves faster, the jet stream – which moves weather systems across the Earth – moves and weakens. That means the cold air trapped at the top of the planet, known as the polar vortex, escapes from its normal boundaries and flows elsewhere, bringing short dips of frigid air that temporarily collide with the an overall warming trend in places, Cohen said.
That happened briefly in January when winter “just made a cameo appearance in the Lower 48,” Cohen said. But most of the time this year, when the polar vortex wandered it hit Europe or Asia with blasts of icy air, not the United States, so there was no offsetting effect on American winter temperatures, he said. he.
Boston didn’t even get a sniff of single-digit temperatures this year, with a winter low of 14 degrees, a record for no deep cold.
And snow? Forget about it, at least in the east and north.
In Fort Kent, in far northern Maine, a lack of snow canceled an annual dog sled race. The town had 46.8 inches (119 cm) of snow this year as of last week, a little more than half as much as normal, the National Weather Service said.
US snow cover in February was the second lowest on record and the third lowest in December, with only January above normal, according to the Rutgers Snow Lab.
There are consequences to a warm winter, said Theresa Crimmins, director of the National Phenology Network.
“Warm winters can lead to earlier, longer and more abundant pest seasons because communities haven’t been hit by the cold,” Crimmins said in an email. “Also, allergy season can be worse—starting earlier, lasting longer, and getting more pollen in the air.”
Because it is warmer, trees and flowers may bloom early. Cherry blossoms are forecast to peak in Washington about two weeks earlier than they did in 2013. Early blooming can break up a complicated time for pollinators and birds.
“A lot of the birds that migrate south for the winter use the whole day as a cue to come north in the spring,” Crimmins said. “In years like this, when plant and insect activity starts much earlier than usual, the birds can reach peak food availability by arriving too late. “
But there is some good news for California with atmospheric rivers and snowstorms likely to rebuild snowpack and fill reservoirs that were dangerously low until a few years ago, Gleason said.
Winter weather expert Cohen, based outside Boston, said the US no longer has four seasons: “We have two seasons. We have summer and we have November.”
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Associated Press writer Patrick Whittle of Portland, Maine contributed.
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Read more about AP’s climate coverage at http://www.apnews.com/climate-and-environment
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Follow Seth Borenstein on X at @borenbears
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