As of Monday, New York City set a record: the deepest run into the winter season without a measurable first snow, at 325 days.

“Measurable,” at least in New York, is defined as snow sticking at a minimum of a tenth of an inch. This stretch of days beats the former deepest push into the season without a first NYC snow, a streak snapped on Jan. 29, 1973. The city usually gets its first snowfall around mid-December; last season it was on Christmas Eve.

Plus, if it doesn’t snow between now and next week in New York City, another marker for the record books will be made: the longest run of consecutive days without measurable snow, period. The U.S.’s largest metropolitan area has not tallied measurable snow since last March 22. The record currently is the 332 days with no snow set on Dec. 15, 2020.

“In reality, there are three separate chances of getting a small amount of snow in NYC, but each of these an extreme long shot.  If we miss the boat on any measurable snow this week, we will likely go for at least a week to 10 days before we have another chance at measurable snow in NYC,” says David Dombek, senior meteorologist at AccuWeather.

If the second record is broken, that means two of the longest snowless periods have happened in recent memory.

And while people taking advantage of a walkable NYC might cheer the chance to leave their boots at home and toss on a lighter jacket, there are bigger implications to these “enjoyable” streaks of unseasonably mild weather.

Namely, it’s what records like this tell us about climate change, and whether some characteristics might simply be chalked up to routine weather phenomenon.

Part of the New York City region’s warmer weather is thanks in part to La Niña — a recurring warming climate pattern originating in the Pacific Ocean that is now on its third consecutive year. Weather experts say it looks like La Niña will be transitioning to a “neutral” impact later this winter into spring.

Yet it’s not just this winter that is milder, and it’s clearly not an East Coast one-off. There’s been a warming trend since the 1970s, as detailed in this graphic.

Summers may feel hotter, but the biggest global warming is in winter

Throughout most of the Mid-Atlantic and Northeast, this winter’s storms have either missed, or they just dumped rain because the air was so warm. The notable exception is Buffalo, N.Y., which has been walloped by several lake-effect storms that dropped snow by the foot and cost dozens of lives because people were trapped in homes or cars.

Some of the same patterns are seen as far west as Chicago, which trends colder and snowier than New York City, in part because it, like Buffalo, is on a Great Lake. In Chicago, snow accumulation has been light and the only remarkable deep freeze the entire season so far was a short-lived, frigid Christmas weekend.

Warmer temperatures may feel soothing on our skin or allow us to push our morning run a bit further, but there are consequences, including for the rest of the year. Importantly, Buffalo’s story is as much a key sign of changing winter patterns as a gray, snowless New York City.

Scientists say extreme weather events, such as the Buffalo blizzard, could happen more often or be more intense as the Earth’s climate changes. That’s because average air temperatures have been warming across the planet for decades, and as they do, the atmosphere holds more water vapor in some locations, increasing the potential for extreme rain and snow events, according to the National Oceanic and Atmospheric Administration.

Warmer temperatures mean it takes longer for the Great Lakes to freeze over in the fall and winter, says David Easterling, chief of the climate assessments section for NOAA’s National Centers for Environmental Information. Open water simply means more fuel for nature’s snow machine known as lake-effect snow.

And there is evidence that strong warming in the Arctic — two times the rate of the rest of the world — can weaken the jet stream, allowing for frigid polar air to penetrate farther south than normal on occasion.

In other areas, warmer temperatures create rain instead of snow, and extreme rain at that, which can pose flooding issues and other aggravations for commuters. Much of the eastern half of the U.S. has seen an increase in extreme rainfall events in recent years.

Summers may be getting warmer, too, but nothing like what’s happening in winter. We are seeing the results of global warming the most during winter, as it is the fastest-warming season in 38 U.S. states. In the Northeast, winter has warmed three times faster than summer in recent decades, says Ilisa Ocko, senior climate scientist with the Environmental Defense Fund.

Northern winters have heated up the most, with more than 5 degrees Fahrenheit of warming in Alaska, Minnesota, Vermont and Wisconsin since 1970. Warming rates are often greater at higher latitudes partly because of a decrease in snow cover, which exposes darker land surfaces that absorb more sunlight, she explains.

As for the western U.S., scant snow and related drought conditions may be improving, but risks of a repeat are very real. Less snow has led to a decline in the amount of snow covering North America, and warmer weather has caused the snowpack — especially in the West — to melt weeks earlier than in the 1960s.

The declining snowpack and earlier snowmelt reduce streamflow, affecting crucial freshwater supply for agricultural, residential and commercial purposes. It also increases the potential for wildfires due to decreases in moisture.

And even a very wet few months for California — including dangerous floods — will only partially pull the region out of its megadrought.

Mother Nature’s head fake

For much of the U.S., warmer winter weather can be devastating to crops and garden plants when they lack the cooler weather they need for a chilled dormancy — an important life stage that, if absent, can lead to less fruit production and weakened plants that are more vulnerable to pests. If plants bloom too early, say before migrating pollinators arrive and the last freeze happens, development cycles will be missed or those early blooms can face a spring freeze.

There’s also a bit of changed psychology to it all. “An ‘average’ winter or ‘typical’ cold streak feels colder to us now, because we are used to the warmer temperatures,” says Ocko.

It’s also true that while winters as a whole are milder, when some areas are hit with a winter storm, singular events have gotten more severe. More than 40% of counties in the country have had their biggest two-day snow totals since 1980.

“Even though the winter has been snowless so far, that does not mean that there can’t be some nasty wintry weather with snow, ice and cold temperatures later in February and even into March. In some winters, the worst weather occurs late in the game,” says AccuWeather’s Dombek.

“If late season cold and snow does not happen and we remain mild with above normal temperatures, then we could set up a situation this spring where blossoms and flowers come out unusually early and then run the risk of being killed by a frost and freeze,” he said. “If that affects agricultural crops such as fruit trees or vineyards, then it could have major impacts on supply and price.”