Global warming is winning the war on Christmas.
Scientists studying temperatures have been recording markedly hotter winters over the past 50 years. For millions of people, the holiday will be hotter than those their grandparents experienced. In the coming decades, many children alive today in the northern hemisphere may come to remember a white Christmas as mostly a memory.
Picking a single day, even Dec. 25, as a barometer for climate change can be misleading since there is so much daily and annual variation. Average seasonal trends do paint a picture, one of pervasive melting. “It’s very fair to say Decembers are warming in some places, and that is translating to a warming Christmas,” says Sean Sublette, a meteorologist with the science nonprofit Climate Matters.
By analyzing data from the National Oceanographic and Atmospheric Administration (NOAA), Sublette says the average December temperatures in 82% of US cities it studied have risen that more by at least 0.5°F since 1970. A full quarter have warmed by at least 3°F. By comparison, only 12% of the 244 cities saw average temperatures drop. And just one (in Idaho) recorded as much as a 3°F decline. The most warming—more than 5°F —occurred in places like Milwaukee, Wisconsin; Portland, Maine; Duluth, Minnesota; Fargo, North Dakota and Burlington, Vermont (average where temperatures have soared 7°F). What has been recorded in Iowa has been typical for the midwest:
Because it takes less energy to warm something up a few degrees that’s already cold, global warming is most evident in colder climates, especially during the coldest times of the year. In the Arctic, warming trends have advanced twice as fast as the global average. Temperatures there hit their second hottest level on record in 2018, according to NOAA, with new records being set almost every year since 2014.
US winters are warming faster than any other season for most of the country. That’s shortening shoulder seasons (spring is now coming 18 days earlier in the Northeast than in the 1850s) and thinning out snow across the country (more precipitation is falling as rain instead of snow).
Some regions of the US will still enter a deep freeze during the winter: The Great Lakes region, the Rocky Mountains, and the far north along the Canadian border. But a vast area across the middle of the US is due for a thaw.
From the southern Colorado plains to the edge of Appalachia, snow will come later, and melt faster, says Sublette. The western US has already seen its snowpack shrink by an area the size of South Carolina (about 41% per state on average), according to the American Geophysical Union (paywall).