Antarctic sea ice likely reached its largest extent of 2026 on September 14, according to NASA and the U.S. National Snow and Ice Data Center. It covered an estimated 17.59 million square kilometers, the third-lowest annual maximum in the satellite record.
Sea ice around Antarctica typically reaches its greatest extent in September, near the end of winter in the Southern Hemisphere, then retreats to a minimum in February.
From 1979 to 2014, total Antarctic sea ice increased by about 1 percent per decade. But because its extent varies considerably from year to year, scientists say it is uncertain whether that increase represented a meaningful change. Satellites recorded three consecutive winter highs from 2012 to 2014.
