Global Snow and Ice - December 2019
NH Snow Cover Extent
|December 2019||Snow Cover Extent||1981-2010 Anomaly||Trend
(out of 54 years)
|million km2||million mi2||million km2||million mi2||million km2||million mi2||Year(s)||million km2||million mi2|
Data Source: Global Snow Laboratory, Rutgers University. Period of record: 1966–2019 (54 years)
The Northern Hemisphere snow cover extent for December 2019 was near average at 43.47 million square km (16.78 million square miles). This value is 510,000 square km (200,000 square miles) below the 1981–2010 average and the 19th smallest December snow cover extent in the 54-year record. December 1980 holds the record for the smallest December snow cover extent at 6.54 million square km (2.52 million square miles) below average. Meanwhile, December 2012 had the largest December snow cover extent on record at 2.87 million square km (1.11 million square miles) above average.
The North American snow cover extent was 310,000 square km (120,000 square miles) above average, resulting in the 18th largest December snow cover extent. Above-average snow cover during December 2019 was present across parts of southern Canada and across much of the north-central contiguous U.S. and parts of the southern Rockies Mountains. Below-average snow cover was observed mainly across parts of western contiguous U.S. and across the Mississippi Valley through parts of the Mid-Atlantic. Alaska's December 2019 snow cover extent tied as the seventh largest December snow cover extent on record. Canada had its 12th largest and the contiguous U.S. had its 20th largest December snow cover extent on record.
Eurasia's December 2019 snow cover extent was the 13th smallest on record at 26.30 million square km (10.16 million square miles), which is 830,000 square km (320,000 square miles) below average. Below-average snow cover was present across much of Europe and parts of western Russia, as well as across parts of central Asia. Above-average conditions covered parts of central and northeastern China, southern Kazakhstan, and southern Scandinavia.
Sea Ice Extent
The sea ice extent data for the Arctic and Antarctic are provided by the National Snow and Ice Data Center (NSIDC) and are measured from passive microwave instruments onboard NOAA Satellites. The sea ice extent period of record is from 1979–2019 for a total of 41 years.
|December 2019||Sea Ice Extent||
(out of 41 years)
|million km2||million mi2||Year(s)||million km2||million mi2|
Data Source: National Snow and Ice Data Center (NSIDC). Period of record: 1979–2019 (41 years)
December 2019 marked the 22nd consecutive December with below average sea ice extent. The average Arctic sea ice extent for December was 11.95 million square km (4.61 million square miles), according to analysis by the National Snow and Ice Data Center, based on data from NOAA and NASA. This value was 890,000 square km (344,000 square miles), or 6.9 percent, smaller than the 1981–2010 average and tied with 2006 as the fifth smallest December sea ice extent since records began in 1979. According to NSIDC, sea ice grew faster than average during December 2019 by an average of 82,100 square km (31,700 square miles)—the third fastest December ice growth rate on record. Only Decembers of 2006 and 2016 had a higher growth rate.
Antarctic sea ice extent during December was 9.30 million square km (3.59 million square miles), according to analysis by the National Snow and Ice Data Center. This value is 1.11 million square km (430,000 square miles), or 10.7 percent, smaller than the 1981–2010 average and also the fifth smallest December extent on record. This was the fourth consecutive December on record with below-average sea ice extent on record.