Winter in the Carolinas was warmer than normal, driven by climate change
Forecasters last fall predicted a warmer, drier winter for the Carolinas, and that's what we got. It's a trend dating from at least the 1970s. In fact, federal weather data show that winters are warming faster than any other season across the region.
Scientists say it's yet another sign of the need to reduce the greenhouse gas emissions that lead to global warming.
"Winter is the fastest-warming season. This is a time where both within the Southeast region and nationally we tend to get very strong trends, very clear signals," said Andrew Pershing, director of climate science at Climate Central, a Princeton, New Jersey, organization of scientists and journalists focused on climate change.
Winter temperatures in major cities across the Carolinas averaged 2 to 3 degrees above normal, defined as the 20-year average from 1991 to 2020, according to data from the National Oceanic and Atmospheric Administration. That's looking at temperatures from December to February.
The warmer winter follows the trend for all of 2021, which was the sixth warmest on record globally and the fourth warmest in the U.S., going back to 1895.
The season started with an unusually warm December - 6-9 degrees above normal across the Southeast. It was slightly below normal in January, then back to 2-3 degrees warmer than normal in February.
This doesn't mean winter doesn't happen. Parts of North Carolina got up to 5 inches of snow during one storm in January.
"Winter is just a highly variable season. And so you still get these wild swings," Pershing said. "This winter seemed to be even more in that highly variable mode, where lots of places, including the Carolinas, were unusually warm in December, and then January was a little cooler."
But altogether, temperatures were above normal.
In Charlotte, for example, this winter's average was 3.3 degrees Fahrenheit above normal. (Normal is defined as the average for the previous 20 years.) The same was true in other cities such as Raleigh (+3.1 degrees), Wilmington (+3.4 degrees) and Columbia and Charleston, South Carolina, both more than 3.5 degrees above normal. (See table.)
Another way to illustrate the long-term warming trend is to look at the cumulative increase in average winter temperatures in recent decades. Since 1970s, Raleigh's average winter temperature is up 4.7 degrees; Greensboro's up 4.4 degrees; Greenville, South Carolina, up 3.9 degrees; and Charlotte and Charleston, both up 3.8 degrees.
Those cumulative average winter temperature increases are larger in winter than any other season, Pershing said.
The Carolinas mirror the national trend. Winter temperatures were above average across much of the lower 48 states, according to NOAA. The average temperature for the contiguous U.S. this winter (excluding Alaska and Hawaii) was 34.8°F, or 2.5°F above average. That ranks among the warmest one-third of winters on record, NOAA said.
Higher temperatures are nice, but they also cause problems.
"We've heard from a number of folks who are talking to farmers, especially in the Southeast. And (during) these warm winters, the plants get going early. But then it only takes one day of cold weather to really set things back," Pershing said.
Frost can mean damaged crops or a disruption of spring blooms, like the cherry blossoms in Washington, D.C., he said.
This story originally appeared in WFAE's weekly climate newsletter, which is published Thursdays. Subscribe at https://www.wfae.org/climate-newsletter-signup.
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