Antarctic sea ice reached its winter maximum on 14 September at 17.59m square kilometres, according to provisional data from the US National Snow and Ice Data Center. That makes it the third-smallest winter peak in the 48-year satellite record. The NSIDC cautions that the data are preliminary and that Antarctic ice extent can fluctuate widely near the seasonal maximum.
Scientists quoted by Carbon Brief describe the persistence of low ice as concerning. Dr Lettie Roach of the Alfred Wegener Institute says that after decades of stable or increasing winter ice, it is concerning to see these low values persisting, but that more years of observations are needed to determine whether this is a structural shift or natural variability. Dr Clare Eayrs of the Korea Polar Research Institute notes that July and August extents were the fifth and fourth lowest on record, respectively, and that regional patterns shifted during the growth season, with the Bellingshausen Sea deficit largely recovering while ice became scarce in the Amundsen Sea and across much of East Antarctica.
At the other pole, Arctic sea ice reached its summer minimum on 12 September at 4.60m sq km, tying with three other years as the joint-10th lowest. Dr Zack Labe of Climate Central says local weather patterns played a large role this year, with cooler, cloudier conditions over parts of the Beaufort and Chukchi seas delaying melt, while the Barents Sea saw its earliest melt-out on record. He stresses that the long-term trend is clearly downward, and that the absence of a new record does not mean the ice is becoming more resilient.
The article also notes that a key dataset used to track Arctic ice thickness, PIOMAS, stopped updating after NOAA terminated a global air-pressure dataset in March 2026, leaving scientists uncertain when production can resume. That adds a practical challenge to monitoring polar change.