Sea Ice Concentration

NOAA / NSIDC • POLAR MONITORING

Sea Ice Concentration

Current Arctic and Antarctic sea-ice extent, concentration, anomalies, trends and higher-resolution products.

ENC WeatherArctic & AntarcticDaily extent • concentration • anomalies • long-term trends

CURRENT EXTENT

Latest Sea Ice Index Values

Daily extent in millions of square kilometers, compared with the 1981–2010 daily average.

Arctic6.717 million km²

1981–2010 avg.8.457

Departure-1.740

Percent-20.6%

Antarctic16.204 million km²

1981–2010 avg.18.158

Departure-1.954

Percent-10.8%

DAILY SEA ICE INDEX

Current Extent & Concentration

The four core daily Sea Ice Index maps are displayed directly rather than hidden behind resource links.

**Arctic Daily Sea Ice Extent**Latest Northern Hemisphere daily extent with the 1981–2010 median ice edge.

**Antarctic Daily Sea Ice Extent**Latest Southern Hemisphere daily extent with the 1981–2010 median ice edge.

**Arctic Daily Sea Ice Concentration**Latest Northern Hemisphere daily sea-ice concentration.

**Antarctic Daily Sea Ice Concentration**Latest Southern Hemisphere daily sea-ice concentration.

MONTHLY SEA ICE INDEX

Extent • Concentration • Anomaly • Trend

Latest completed-month products for both hemispheres.

**Arctic Monthly Extent**Latest completed-month Arctic extent and median ice edge.

**Antarctic Monthly Extent**Latest completed-month Antarctic extent and median ice edge.

**Arctic Monthly Concentration**Latest completed-month Arctic sea-ice concentration.

**Antarctic Monthly Concentration**Latest completed-month Antarctic sea-ice concentration.

**Arctic Concentration Anomaly**Latest completed-month Arctic concentration departure from the 1981–2010 reference.

**Antarctic Concentration Anomaly**Latest completed-month Antarctic concentration departure from the 1981–2010 reference.

**Arctic Concentration Trend**Long-term Arctic concentration trend for the latest completed month.

**Antarctic Concentration Trend**Long-term Antarctic concentration trend for the latest completed month.

SEA ICE INDEX TOOLS

Viewer, Data & Comparison

The full NSIDC tools remain available in addition to the data shown above.

ViewerSea Ice Index Image Viewer

Daily and monthly Arctic/Antarctic extent, concentration, anomalies and trends.

Open source ↗DatasetSea Ice Index Version 4

Source data, methods and documentation for the long-term record.

Open source ↗CompareCharctic Interactive Graph

Compare Arctic and Antarctic daily extent across years.

Open source ↗ArchiveSea Ice Index Data Archive

Archived daily/monthly images, CSV data and GIS files.

Open source ↗

HIGHER RESOLUTION / NEAR REAL TIME

Additional Sea-Ice Products

These complement the 25-km Sea Ice Index with operational and higher-resolution products.

MASIEMASIE-NH Daily Viewer

Operational Arctic sea-ice extent from the U.S. National Ice Center, including regional products.

Open source ↗4 km ArcticMASAM2 Version 2

Daily 4-km Arctic sea-ice concentration with PNG and netCDF products.

Open source ↗Global NRTNISE Version 5

Near-real-time daily global sea-ice concentration and snow extent.

Open source ↗Raw DataNOAA@NSIDC Sea Ice Archive

Direct access to Sea Ice Index images, CSV values and source files.

Open source ↗

WHAT TO COMPARE

Concentration vs. Extent

The two measurements describe different aspects of the ice cover.

Concentration

Percentage of each roughly 25-km grid cell covered by sea ice.

Extent

Total ocean area with at least 15% sea-ice concentration.

Anomaly

Departure from the 1981–2010 climatological concentration for the month.

Trend

Longer-term concentration change, expressed as percent change per decade.