Press Release

Arctic sea ice at maximum extent for 2021

Arctic sea ice has likely reached its maximum extent for the year, at 14.77 million square kilometers (5.70 million square miles) on March 21, 2021, according to scientists at the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder. The 2021 maximum is tied with 2007 for seventh lowest in the 43-year satellite record. 

This NASA Blue Marble image shows Arctic sea ice on March 21, 2021, when sea ice reached its maximum extent for the year. Sea ice extent for March 21 averaged 14.77 million square kilometers (5.70 million square miles), tied with 2007 as the seventh-lowest in the satellite record. Image credit: NSIDC / NASA Earth Observatory. High-resolution image

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

NSIDC is part of the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder. The NSIDC Arctic Sea Ice News & Analysis is supported in part by NASA.

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

Read the NASA feature here