Arctic sea ice has likely reached its minimum extent for the year, at 4.72 million square kilometers (1.82 million square miles) on September 16, 2021, according to scientists at the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder. The 2021 minimum is the twelfth lowest in the nearly 43-year satellite record. The last 15 years are the lowest 15 sea ice extents in the satellite record.