2023 Antarctic sea ice winter maximum is lowest on record by a wide margin

Overview of conditions

On September 10, 2023, sea ice in the Antarctic reached an annual maximum extent of 16.96 million square kilometers (6.55 million square miles), setting a record low maximum in the satellite record that began in 1979. This year’s maximum is 1.03 million square kilometers (398,000 square miles) below the previous record low set in 1986. It is also 1.75 million square kilometers below (676,000 square miles) below the 1981 to 2010 average Antarctic maximum extent.

Sea ice extent is markedly below average north of Queen Maud Land and west of the Antarctic Peninsula. Other low areas include the Indian Ocean and Ross Sea. Extent is above average stretching out of the Amundsen Sea.

The Antarctic maximum extent is one of the earliest on record, having reached it 13 days earlier than the 1981 to 2010 median date of September 23. The interquartile range [the central 50 percent of the full data range] for the date of the Antarctic maximum is September 18 to September 30.

Conditions in context

This year marks a significant record low maximum in Antarctic sea ice extent (Figure 2). Since early April 2023, sea ice maintained record low ice growth. From early to mid-August, growth slowed considerably, maintaining a difference of nearly 1.5 million square kilometers (579,000 square miles) between 2023 and 1986, the second lowest year on satellite record. After that period, ice growth quickened and narrowed the gap to about 1 million square kilometers (386,000 square miles). This is the first time that sea ice extent has not surpassed 17 million square kilometers (6.56 million square miles), falling more than one million square kilometers below the previous record low maximum extent set in 1986.