Antarctic Sea Ice Hits Third-Lowest Annual Maximum

Antarctic sea ice likely reached its annual maximum on September 14, 2026, at an estimated 17.59 million square kilometers, the third-lowest maximum in the satellite record, according to NASA Earth Observatory. ^[1] Scientists define sea ice extent by counting ocean areas where ice concentration is at least 15 percent. ^[1]

Antarctic sea ice typically expands through Southern Hemisphere winter and peaks in September, but its extent varies considerably from year to year. ^[1] NASA notes that scientists are still assessing whether the broad decline seen since 2016 reflects a lasting change or natural statistical fluctuation, so a single year’s maximum does not establish a long-term trend. ^[1]