NOAA's National Centers for Environmental Information
Northern Hemisphere Snow Cover Extent
| October 2024 | Snow Cover Extent | Anomaly 1991-2020 | Trend per decade | Rank (57 years) | Record | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| million km² | million mi² | million km² | million mi² | million km² | million mi² | Year(s) | million km² | million mi² | |||
| Northern Hemisphere | 18.88 | 7.29 | -0.29 | -0.11 | +0.39 | +0.15 | Largest | 25th | 1976 | 25.72 | 9.93 |
| Smallest | 33rd | 1988 | 12.78 | 4.93 | |||||||
| North America | 7.62 | 2.94 | -0.86 | -0.33 | +0.14 | +0.05 | Largest | 47th | 2020 | 10.26 | 3.96 |
| Smallest | 11th | 1979 | 6.36 | 2.46 | |||||||
| Eurasia | 11.27 | 4.35 | +0.59 | +0.23 | +0.25 | +0.10 | Largest | 18th | 1976 | 17.22 | 6.65 |
| Smallest | 40th | 1988 | 5.58 | 2.15 | |||||||
Data Source: Global Snow Laboratory, Rutgers University. Period of record: 1967–2024 (57 years)
The Northern Hemisphere snow cover extent for October 2024 was 18.88 million square kilometers (7.29 million square miles), which was near average; 290,000 square kilometers (110,000 square miles) below the 1991–2020 average. This was the 25th-largest Northern Hemisphere October snow cover extent on record. Snow cover was below average in North America and Greenland while it was slightly above average in Eurasia.
The North America and Greenland snow cover extent for October was 7.62 million square kilometers (2.94 million square miles), which was 860,000 square kilometers (330,000 square miles) below the 1991–2020 average. This ranked as the 11th-smallest October snow cover extent on record for North America. As shown on the Rutgers University Global Snow Lab monthly departure map, areas of below average snow cover extent were widespread across southern Canada extending southward through the U.S. Rockies, as well as a large part of the northern tier of Canada and parts of the Canadian Archipelago. Areas of above-average snow cover included parts of central Alaska and an area stretching from the west coast of British Columbia into parts of central Canada, as well as small parts of northeastern Canada.
Snow cover extent over Eurasia in October was slightly above average at 11.27 million square kilometers (4.35 million square miles), which was 590,000 square kilometers (230,000 square miles) below the 1991–2020 average. This was the 18th-largest October snow cover extent on record for Eurasia. The past 13 Octobers have had snow cover extent near or above average.
October snow cover extent was above average across much of Siberia extending into northern Mongolia and parts of northern Kazakhstan. Parts of Scandinavia and eastern Europe also had above average snow cover extent in October. The most widespread areas of below average snow cover extent occurred in southern and western Russia, southwestern China and parts of the Himalayas.
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 1979–2024 for a total of 46 years.
| October 2024 | Sea Ice Extent | Anomaly 1991-2020 | Trend per decade | Rank (46 years) | Record | ||||
|---|---|---|---|---|---|---|---|---|---|
| million km² | million mi² | Year(s) | million km² | million mi² | |||||
| Northern Hemisphere | 5.94 | 2.29 | -20.69% | -10.41% | Largest | 43rd | 1986 | 9.48 | 3.66 |
| Smallest | 4th | 2020 | 5.33 | 2.06 | |||||
| Southern Hemisphere | 16.55 | 6.39 | -9.22% | -0.22% | Largest | 45th | 2013 | 19.02 | 7.34 |
| Smallest | 2nd | 2023 | 16.20 | 6.25 | |||||
| Globe | 22.49 | 8.68 | -12.56% | -3.19% | Largest | 46th | 1980 | 27.75 | 10.71 |
| Smallest | 1st | 2024 | 22.49 | 8.68 | |||||
Data Source: National Snow and Ice Data Center (NSIDC). Period of record: 1979–2024 (46 years)
Globally, October 2024 sea ice extent was the lowest in the 46-year October record at 22.49 million square kilometers (8.68 million square miles). This is 3.2% (3.23 million square kilometers; 1.25 million square miles) below the 1991–2020 average, and slightly below last year's previous record-low October extent. October sea ice extent has been below average in each of the past 10 years.
According to the National Snow & Ice Data Center during October much of the Arctic was markedly warmer than average and sea level pressure was low over most of the Arctic. The pressure pattern helped to push ice northwards in the Kara and Barents Seas and bring in warmer air towards the central Arctic Ocean.
For the month as a whole, the average Arctic sea ice extent was the fourth smallest in the satellite record at 5.94 million square kilometers (2.29 million square miles). This is 1.55 million square kilometers (600,000 square miles) below the 1991–2020 average. The average October Arctic sea ice extent has been at least nominally below the 1991–2020 average in each of the past 18 years. October sea ice extent was below-average in areas that included the Beaufort Sea, the Canadian Archipelago, the Barents Sea, and the Central Arctic Ocean. Sea ice extent was above average in areas that included the East Siberian Sea and the Japan Sea.
The average Antarctic sea ice extent was the second smallest on record for October (16.55 million square kilometers or 6.39 million square miles). This is 1.68 million square kilometers (650,000 square miles) below the 1991–2020 average and approximately 350,000 square kilometers (140,000 square miles) greater than the lowest on record October Antarctic sea ice extent that occurred last year.