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.

September 2023 set a record for the lowest global September sea ice extent on record. This primarily resulted from record-low sea ice extent in the Antarctic, which saw its fifth consecutive month with the lowest sea ice extent on record. September 2023 sea ice extent, globally, was 1.51 million square kilometers (590,000 square miles) less than the previous record low from September 2016.

The Arctic sea ice extent for September 2023 ranked as the fifth smallest in the satellite record at 4.37 million square kilometers (1.69 million square miles). This was 1.21 million square kilometers (470,000 square miles) below the 1991–2020 average.

On September 19, NSIDC announced that Arctic sea ice likely reached its annual minimum extent of 4.23 million square kilometers (1.63 million square miles). This year's Arctic minimum ranks sixth lowest in the 45-year record. The last 17 years—2007 to 2023—comprise the 17 lowest sea ice extent minimums on record.

Sea ice extent was below average in the Canadian archipelago and the Barents, Beaufort, Chukchi, East Siberian, and Kara Seas. The central Arctic Ocean, the Greenland Sea, and the Baffin and Hudson Bays had near-normal extents for September. The Laptev Sea, which is located off the coast of northern Siberia, had slightly above-average sea ice extent for September.

Sea ice extent in Antarctica continued to track at record lows. Seven of the nine 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 September 2023 Antarctic sea ice extent ranked lowest on record at 16.80 million square kilometers (6.49 million square miles), or 1.81 million square kilometers (700,000 square miles) below the 1991–2020 average. This was 880,000 square kilometers (340,000 square miles) lower than the previous record low from September 1986.

NSIDC announced a record-low annual Antarctic sea ice maximum extent at 16.96 million square kilometers (6.55 million square miles) on September 10. This set a record low maximum in the satellite record that dates back to 1979, beating out the previous record low set in 1986 by 1.03 million square kilometers (398,000 square miles).