In May 2013, there was record-setting loss of Eurasian spring snow cover and a below normal spring snow cover extent in North America in June—the fourth lowest on record. This is the sixth year in a row that Eurasia has set a new record low in either May or June snow extent. Scientists have attributed this to rapid snow melt, rather than to anomalously low winter snow accumulation prior to melting. Because Arctic land areas are almost completely covered in snow before the melting season, variability in the spring snow cover extent is controlled largely by surface temperatures: the warmer the surface temperatures, the earlier the onset of the melt.
Over the long-term, the rate of warming in the Arctic has reduced the area covered by snow each year in the Northern Hemisphere. The rate of snow cover loss over Northern Hemisphere land areas in June between 1979 and 2013 is -19.9 percent per decade (relative to the 1981-2010 mean)–a faster decline than September sea ice loss of 13.7 percent per decade over the same period.
More information can be found in the Snow chapter of the Arctic Report Card: Update for 2013.