Arctic sea ice ties 10th-lowest minimum as Antarctic ice hits record lows

Arctic sea ice reached its 2026 low point on Sept. 12, tying for the 10th-lowest minimum in the satellite record after an unusually cool and stormy summer over the Arctic Ocean, the National Snow and Ice Data Center (NSIDC) said in an analysis published Oct. 7. Around Antarctica, meanwhile, sea ice has been at record daily lows since Oct. 2.

The NSIDC analysis, titled “Stranger Things” in the 2026 Arctic, describes a season of contrasts. Global air temperatures were at or near record highs in June, July and August, yet conditions over the Arctic Ocean itself stayed cool and stormy. The Sept. 12 minimum tied 2008, 2010 and 2025 for 10th lowest, a ranking NASA and NSIDC reported on Sept. 23.

The numbers

According to NASA, the ice covered about 4.6 million square kilometers (1.78 million square miles) at the minimum. Averaged over the whole of September, NSIDC put Arctic extent at 4.81 million square kilometers (1.86 million square miles). That was the 13th lowest for the month in the satellite record and 1.6 million square kilometers (618,000 square miles) below the 1981 to 2010 average.

The long-term direction has not changed. NSIDC calculates the September trend as a loss of 74,100 square kilometers (28,600 square miles) per year, or 11.6 percent per decade. Since 1979, September ice has shrunk by 3.24 million square kilometers (1.25 million square miles), an area the center said is equivalent to twice the size of Alaska. NASA noted that the 20 lowest annual minimums since continuous satellite measurements began in late 1978 have all occurred from 2007 through 2026.

Older, thicker ice has largely gone. Since 2007, the extent of multiyear ice at the end of the melt season has varied between 1.3 million and 1.9 million square kilometers, compared with roughly 3.5 million square kilometers in the 1980s, NSIDC said. Since 2012, the oldest ice, more than four years old, “has nearly disappeared,” according to the analysis.

A cool, stormy summer

NSIDC links the middling ranking mainly to weather. A pronounced area of low pressure centered near the North Pole lingered through June, July and August, and air temperatures over the ocean ran below average, most clearly in June, when melt started late. The same cyclonic pattern contributed to a late melt-out in the Beaufort and Chukchi seas, where the ice was dominated by first-year ice, which is thinner and more prone to melting out completely.

NSIDC reported that a loose ice pack on the Atlantic side of the Arctic Ocean allowed the Swedish icebreaker Oden to reach the North Pole. The Northern Sea Route along the Eurasian coast appeared largely free of ice, while heavy ice blocked M’Clure Strait at the west end of the deepwater northern route of the Northwest Passage, and significant ice remained in the southern route, known as Amundsen’s route.

After the minimum, open water refroze quickly, and NSIDC described the post-minimum freeze-up as rapid. In early October, extent was still below average along the Eurasian coast, especially in the Kara and Barents seas.

In NASA’s Sept. 23 release, Linette Boisvert, a sea ice scientist at NASA’s Goddard Space Flight Center, said increased cloud cover over the last decade has kept sunlight from accelerating melt further. Walt Meier, a senior research scientist at NSIDC, summed up the recent run of minimums: “We’ve plateaued, but we’re still low relative to the earlier part of the record.”

Antarctica heads the other way

In the Southern Hemisphere, sea ice reached its winter maximum on Sept. 14, the third lowest in the satellite record, and then dropped sharply through the rest of the month, according to NSIDC. The September average was 17.32 million square kilometers (6.69 million square miles). Since Oct. 2, daily extent has fallen to record lows for the time of year, surpassing the records set in 2023. The losses after the maximum were concentrated in the Ross and Amundsen seas and the Indian Ocean sector.

NASA has noted that Antarctic sea ice varies more from year to year than Arctic ice because it is not bounded by land. The agency said the Antarctic maximum has generally been lower in recent years, but that Boisvert and Meier are cautious about calling this a long-term trend.

Why it matters

The 2026 season shows how strongly a single summer’s weather can shape the headline number. Persistent storms and cloud kept this year’s Arctic minimum well short of a record, yet it still sits inside the run of the 20 lowest minimums on record, all of them since 2007, and the thick multiyear ice that once dominated the central Arctic has not come back.

For ships, the picture was mixed: a largely open Northern Sea Route, but blocked deepwater passages through the Canadian Arctic. In the south, record daily lows in early October follow a third-lowest maximum, extending a period of very low Antarctic ice that includes the 2023 records, even as scientists hold back from calling it a trend.

The caveats

The figures come from satellite passive microwave records. NASA said the continuous record began with NASA’s Nimbus-7 satellite in October 1978 and continues today with the Advanced Microwave Scanning Radiometer 2 on Japan’s GCOM-W satellite. The Antarctic record lows are daily values as of early October, not a final seasonal tally.

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