Warming winters mean shorter Boston cold streaks

Cold weather streaks in Boston have been getting five days shorter on average since 1970, according to a new Climate Central analysis.

Why it matters: Few people love chilled-to-the-bone cold snaps — but extended periods of chilly weather are key for some farmers and for winter sports lovers, building essential snowpack and more.

Zoom in: Prolonged cold snaps still happen — Boston's longest of 2023 lasted 6 days.

Yes, but: The city's longest cold streak between 1970 and 2023 lasted 40 days — in 1985.

The big picture: Cold streaks are largely getting shorter on average nationwide, per the report from Climate Central, a climate research and communications nonprofit.

• "Winter's longest cold streaks have gotten shorter since 1970 in 98% of 240 U.S. locations analyzed," per the report.
• Nearly half of the locations they analyzed have seen streaks shrink by at least a week, researchers found.

What they did: Climate Central defines a "winter cold streak" as "at least two consecutive December-February days with average temperatures below the 1991-2020 winter normal average temperature" at a given location.

What they're saying: "This will continue to warm year over year. This could be the coldest winter of the rest of your life," UMass Lowell climate science professor Mathew Barlow told Axios.

• He said people should think of recent warmer temperatures not as a "new normal," but as the first part of ever-increasing temperatures until carbon emissions are significantly cut back.

The local New England ecosystem is under just as much threat from warming winters as the rest of the planet, with migrating birds, hibernating animals and agriculture at risk, Barlow said.

• The changes can lead to increases in "weather whiplash" that can affect humans, animals and plants.

Zoom out : The Climate Central report found that the rest of New England's cities saw even fewer cold days than Boston.

• Cold streaks in Hartford, Connecticut; Providence, Rhode Island; Springfield, Massachusetts; and Burlington, Vermont were all eight days shorter.
• Manchester, New Hampshire's cold streaks were six days shorter.
• New York City's were seven days shorter.

Warmer states, meanwhile, are seeing streaks of wintery temperatures nearly disappear.

• Las Vegas' cold streaks are 21 days shorter on average, per the report.
• Fresno, California's are 14 days shorter.
• Nearly all measured metro areas saw shorter cold streaks, except for Los Angeles, California; Eureka, California; and Idaho Falls, Idaho, where cold phases got longer.

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