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Arctic sea ice has likely reached its maximum extent for the year, at 14.33 million square kilometers (5.53 million square miles) on March 22, according to scientists at the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder. The 2025 maximum sea ice extent is the lowest in the 47-year satellite record, falling short of the previous record low of 14.41 million square kilometers (5.56 million square miles) set on March 7, 2017.

Melting on the Antarctic Ice Sheet for the 2024 to 2025 season began with above average melt extents in all regions, but melt extent dropped to nearly zero or below average from February 1 to March 15. Net accumulation of snow, part of the ice sheet’s surface mass balance, was far above average for the year, helping reduce the ice sheet’s net contribution to sea level rise for this period.

NSIDC expertise has contributed to the enhancement of Xarray, a popular open-source tool used for data analysis and visualization. DataTree has been integrated into Xarray.

Antarctic sea ice has likely reached its minimum extent for the year, at 1.98 million square kilometers (764,000 million square miles) on March 1, 2025, according to scientists at the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder. The 2025 minimum is effectively tied with 2022 and 2024 for second lowest in the 47-year satellite record. It is 190,000 square kilometers (73,000 square miles) above the record low, set in 2023. The last four minimums have been the lowest on record.

On March 1, Antarctic sea ice likely reached its minimum extent of 1.98 million square kilometers (764,000 square miles), tying for second lowest extent with 2022 and 2024 in the 47-year satellite record. This is the fourth consecutive year that Antarctic sea ice has reached a minimum below 2.0 million square kilometers (772,000 square miles).