Is a 'White Christmas' destined to be just a dream from now on?
A white Christmas seems to be slowly morphing from a reliable reality to a dream of snowy holidays past for large swaths of the United States in recent decades.
Analysis of 40 years of December 25 U.S. snow measurements shows that less of the country now has snow for Christmas than in the 1980s.
That's especially true in a belt across the nation's midsection — from Baltimore to Denver and a few hundred miles farther north. And snow that falls doesn't measure up to past depths.
Scientists say the decline in the number of white Christmases is relatively
small and caution about drawing conclusions. But it's noticeable and
matters mightily to some people like George Holland.
The retired Dubuque, Iowa, educator known for his front yard nativity scenes said snow on Christmas is supposed to be part of the holiday:
"The one that makes my heart warm is after going to midnight Mass and coming outside and it's snowing."
But the weather in Dubuque hasn't cooperated in recent years. "We don't
have white Christmas,'' said boutique owner Bill Kaesbauer. "We haven't had any in years."
The last one was in 2017 in Dubuque, which weather records show used to
have white Christmases nearly two out of three years.
The average December temperature in the continental U.S. was a tad below freezing from 1981 to 1990, federal weather records show. And from 2011 to 2020, it was up to an average slightly
above 35 degrees (just under 2 degrees Celsius), considerably above the freezing mark.
But what did that warming trend,
natural weather variability and a western megadrought mean to white Christmases?
From 1981 to 1990, on average, almost 47% of the country had snow on the ground Christmas Day, with an average depth of 3.5 inches (8.8 centimeters), according to an analysis of ground observation data by the University of Arizona for The Associated Press. From 2011 to 2020, Christmas
snow cover was down to 38%, with an average depth of 2.7 inches (6.8 centimeters).
The change was particularly pronounced in a swath from about the Mason-dixon line to just north of
Detroit, Chicago, and Nebraska. The Christmas snow cover average there went from nearly 55% in the 1980s to
slightly above 41% now, the Arizona
data shows. Average snow depth fell from 3.5 inches (8.8 centimeters) to 2.4 inches (6 centimeters).
The numbers are small enough that it's diffi- cult to tell whether this is a meaningful trend and, if so, whether climate change or natural weather variability is the cause, said University
of Arizona atmospheric scientist Xubin Zeng, who ran the data.
Still, Zeng, who has published studies on de- creasing snowpack in the western U.S. being connected to climate change, said the down- ward slide of white Christmases is consistent with global warming.
In 20 to 30 years "with climate warming, the prospects of a white Christmas in many parts of the U.S.A. will be slim indeed," said Mark
Serreze, director of the National Snow and Ice Data Center in Boulder, Colorado.
A separate analysis by the National Oceanic and Atmospheric Administration looks at "climate normals" — 30-year periods for about
5,000 weather stations across the lower 48 states. Comparing normals for 1981-2010 to normals for 1991-2020 shows more stations are seeing statis- tical odds for a white Christmas shrink, but the agency cautions against drawing a conclusion about any trend.
In much of Iowa and eastern Washington, the changes are bigger than elsewhere, according to NOAA. From 1981 to 2010, Dubuque's chance for a white Christmas was 63% but it's now down to 42%. Walla Walla, Washington's chance
of getting a white Christmas dropped in half from 19% in 1981 to 2010 to 9.5% now.
Denver's airport station went from 40% chance of Christmas snow from 1981 to 2010 to 34%. Chicago, St. Louis, Kansas City, Salt Lake City, Milwaukee, Fort Wayne, Topeka, Des Moines, Akron, Albany, Olympia, Rapid City, and Oklahoma City airports saw drops of three or four percentage points.
The line where there's at least a 10% chance for a white Christmas moved noticeably north with the new normals, said NOAA climate scientist Imke Durre. And the nation's capital went from 10% to 7%.
"The movement of that line is consistent with a warmer December," Durre said.
New York, Philadelphia and Concord, New Hampshire, recorded small increases in chances of Christmas snow on the ground.