NOAA's National Centers for Environmental Information
Northern Hemisphere Snow Cover Extent
| October 2023 | Snow Cover Extent | Anomaly 1991-2020 | Trend per decade | Rank (56 years) | Record | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| million km² | million mi² | million km² | million mi² | million km² | million mi² | Year(s) | million km² | million mi² | |||
| Northern Hemisphere | 18.73 | 7.23 | -0.44 | -0.17 | +0.40 | +0.15 | Largest | 25th | 1976 | 25.72 | 9.93 |
| Smallest | 32nd | 1988 | 12.78 | 4.93 | |||||||
| North America | 8.15 | 3.15 | -0.33 | -0.13 | +0.15 | +0.06 | Largest | 28th | 2020 | 10.26 | 3.96 |
| Smallest | 29th | 1979 | 6.36 | 2.46 | |||||||
| Eurasia | 10.58 | 4.08 | -0.10 | -0.04 | +0.25 | +0.10 | Largest | 24th | 1976 | 17.22 | 6.65 |
| Smallest | 33rd | 1988 | 5.58 | 2.15 | |||||||
Data Source: Global Snow Laboratory, Rutgers University. Period of record: 1967–2023 (56 years)
The Northern Hemisphere snow cover extent for October 2023 was 18.73 million square kilometers (7.23 million square miles), which was 440,000 square kilometers (170,000 square miles) below the 1991–2020 average.
This ranked as the 25th-largest Northern Hemisphere October snow extent on record.
The North America and Greenland snow cover extent for October was 8.15 million square kilometers (3.15 million square miles), which was 330,000 square kilometers (130,000 square miles) below the 1991–2020 average. This ranked as a near-normal October snow cover extent (28th largest, 29th smallest) for the region.
Above-average October snow cover extent was observed across parts of the north-central and northeastern U.S., eastern Alaska, and central and southeastern Canada. Parts of the central plains of the U.S. and western and north-central Canada had below-average extent.
Snow cover extent over Eurasia in October was 10.58 million square kilometers (4.08 million square miles), which was 100,000 square kilometers (40,000 square miles) below the 1991–2020 average. This was the 24th-largest October Eurasian snow cover extent on record.
Most of northern Europe, western and eastern Russia, and central China had above-average snow cover extent this month. Parts of Mongolia, southern Russia, Uzbekistan, northern Kazakhstan, and western Europe had below-average extent for October.
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 1979–2023 for a total of 45 years.
| October 2023 | Sea Ice Extent | Anomaly 1991-2020 | Trend per decade | Rank (45 years) | Record | ||||
|---|---|---|---|---|---|---|---|---|---|
| million km² | million mi² | Year(s) | million km² | million mi² | |||||
| Northern Hemisphere | 6.37 | 2.46 | -14.95% | -10.41% | Largest | 39th | 1986 | 9.48 | 3.66 |
| Smallest | 7th | 2020 | 5.33 | 2.06 | |||||
| Southern Hemisphere | 16.20 | 6.25 | -11.14% | 0.00% | Largest | 45th | 2013 | 19.02 | 7.34 |
| Smallest | 1st | 2023 | 16.20 | 6.25 | |||||
| Globe | 22.57 | 8.71 | -12.25% | -3.03% | Largest | 45th | 1980 | 27.75 | 10.71 |
| Smallest | 1st | 2023 | 22.57 | 8.71 | |||||
Data Source: National Snow and Ice Data Center (NSIDC). Period of record: 1979–2023 (45 years)
October 2023 set a record for the lowest global October sea ice extent on record. This primarily resulted from record-low sea ice extent in the Antarctic, which saw its sixth consecutive month with the lowest sea ice extent on record. October 2023 sea ice extent, globally, was 970,000 square kilometers (380,000 square miles) less than the previous record low from October 2016.
The Arctic sea ice extent for October 2023 ranked as the seventh smallest in the satellite record at 6.37 million square kilometers (2.46 million square miles). This was 1.12 million square kilometers (430,000 square miles) below the 1991–2020 average.
Sea ice extent was below average in the Barents, Beaufort, and Chukchi Seas, Baffin and Hudson Bays, and the Canadian archipelago. The central Arctic Ocean and the east Siberian and Kara Seas had near-normal extents for October. The Bering, Greenland, and Laptev Seas and the Seas of Japan and Okhotsk had slightly above-average sea ice extent for October.
Sea ice extent in Antarctica continued to track at record lows. Eight of the ten months in 2023 have seen Antarctic sea ice extent at record-breaking low levels. The remaining two months saw extent at second (March) and third (April) lowest levels on record.
The October 2023 Antarctic sea ice extent ranked lowest on record at 16.20 million square kilometers (6.25 million square miles), or 2.03 million square kilometers (780,000 square miles) below the 1991–2020 average. This was 980,000 square kilometers (380,000 square miles) lower than the previous record low from October 1986.