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.

“This new record low is yet another indicator of how Arctic sea ice has fundamentally changed from earlier decades,” said NSIDC senior research scientist Walt Meier. “But even more importantly than the record low is that this year adds yet another data point to the continuing long-term loss of Arctic sea ice in all seasons.”

The record low Arctic maximum extent follows a near-record-low minimum extent for Antarctic sea ice, which was set on March 1, 2025, at 1.98 million square kilometers (764,000 square miles), and tied for the second lowest annual minimum in the satellite record.

(NSIDC scientists stress that the Arctic sea ice extent number is preliminary—weather conditions could change the annual maximum ice extent. NSIDC will issue a full analysis in early April.)