NSIDC sea ice area and extent

Arctic sea ice

NSIDC sea ice concentration animation for last 10 days

Update 2 Aug 2025: NSIDC introduced a new dataset for 2025 that uses AMSR2 satellite data instead of the current SSMIS satellite data. This new dataset is only available for the year 2025, previous years still use SSMIS. But it turns out that the new data are biased low compared to the SSMIS data: the bias for recent days is about 0.2 million km2 for sea ice area and 0.1 million km2 for sea ice extent. For consistency with previous years, I'll keep using the gridded SSMIS data for 2025 here (for as long as they are still updated daily) rather than the AMSR2 data.

The graphs and data below are calculated from the gridded SSMIS sea ice concentration data from the National Snow and Ice Data Center (NSIDC).

Technical notes:

This page uses daily data, rather than the 5-day averages that are used on some other websites.
The data for 2025 are near-real-time data and may be subject to small revisions by NSIDC at the end of the year.
The "pole hole" (a small area around the North Pole of about 29k square km where data are unavailable) is assumed to be 100% covered by sea ice. This assumption may be replaced by an interpolation later.

Arctic sea ice area