News Release
  • Sea ice

Arctic sea ice has reached minimum extent for 2021

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. 

This NASA Blue Marble image shows Arctic sea ice on September 16, 2021, when sea ice reached its minimum extent for the year. Sea ice extent for September 16 averaged 4.72 million square kilometers (1.82 million square miles)—the twelfth lowest in the satellite record. — Credit: NSIDC / NASA Earth Observatory

“We had a reprieve this year—a cool and stormy summer with less ice melt,” said Mark Serreze, director of NSIDC. “But the amount of old, thick sea ice is as low as it has ever been in our satellite record.”

Please note that the Arctic sea ice extent number is preliminary—continued melt conditions could still push the ice extent lower. NSIDC will issue a formal announcement at the beginning of October with full analysis of the possible causes behind this year’s ice conditions, interesting aspects of the melt season, the set up going into the winter growth season ahead, and graphics comparing this year to the long-term record.

For more details and images, please see the NSIDC Arctic Sea Ice News & Analysis page.

Read the NASA feature here