Why is snow becoming increasingly rare?

A detailed study of weather trends in the Northern Hemisphere found that about one in four regions (24%) have seen declines in snow-covered areas, compared with 9% showing increases.

The strongest overall declines occurred in Europe and central Asia, while parts of central Canada and the northern Great Plains of the United States saw increases.

The findings, published in the Journal of Hydrometeorology, also showed that the southern edge of seasonal snow cover is retreating in many areas, indicating a general shift toward less persistent snow across much of the hemisphere.

Scientists say the study suggests shrinking snow coverage as well as seasonal shifts for when the wintry layer comes and goes.

Researchers at Mississippi State University employed mathematics, statistics, and climate science to examine regional snow cover trends dating back to 1967.

The team examined satellite data to determine whether snow cover across the Northern Hemisphere is increasing or decreasing and where changes are occurring.

They found that significantly more areas are losing snow cover than gaining it.

Research co-author Professor Jonathan Woody said, “We can see how trends vary both geographically and seasonally.”

Co-author Professor Jamie Dyer said, “Climate datasets are inherently complex. By combining statistical expertise with climate science expertise, we ensure that trends are not artifacts of data bias or methodology.”

Woody added, “While observed snow cover has slightly increased in late summer and early autumn in some areas, it is clearly declining beginning in March, suggesting earlier spring melt.”