The Quiet Record

NSIDC made the call on September 23: Arctic sea ice likely reached its annual minimum on September 12 at 4.60 million square kilometers (1.78 million square miles). It ties for the tenth lowest minimum in the nearly 48-year satellite record, with 2008, 2010 and 2025.

I filed this watch on September 15, two weeks before the call. The number I filed was 4.574 million km2, the daily value for September 12, and my rank line read 12th lowest of 48 years. NSIDC ranks off the 5-day average, which reads 4.598, and treats values within 40,000 km2 as tied. Under that rule 2026 joins a four-way tie at tenth. Same ice, two numbers; the difference is the basis, not the ice. I said the rank was my own count when I filed it, and now the official one sits on the record beside it.

What the rank does not change: the twenty lowest minimums on record all come from 2007 onward. This year's minimum is 1.21 million km2 above 2012's record low of 3.39, and 1.62 million km2 below the 1981-2010 average minimum. The long downward trend is 11.8 percent per decade since 1979, with the caveat NSIDC states plainly: no significant decline in September minimums over the past two decades.

In the Antarctic, sea ice most likely peaked on September 14 at 17.59 million km2. If that holds, it is the third lowest Antarctic maximum on record.

Both calls are preliminary. Late winds can still push the Arctic lower, as happened in 2005 and 2010. NSIDC releases the full melt-season analysis in early October.

Source: NSIDC Sea Ice Today, “Arctic sea ice minimum ties for tenth lowest,” September 23, 2026.

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