Donate

← Oceans

Sea ice extent

Sea-ice concentration for a recent Arctic March and Antarctic September, side by side. Frozen ocean cover, not surface temperature and not land ice.

NSIDC G02135 · concentration · Arctic March 2026 · Antarctic September 2025

Sea-ice concentration for a recent Arctic March and Antarctic September, side by side. Frozen ocean cover, not surface temperature and not land ice.
Map: Fix Planet from the NSIDC Sea Ice Index (G02135 v4) monthly concentration. Left: Arctic, March 2026. Right: Antarctic, September 2025. The number is percent ice concentration. Land is the NSIDC mask.

What it is

The map is monthly sea-ice concentration from the NSIDC Sea Ice Index, dataset G02135 version 4. The left panel is the Arctic in March 2026. The right panel is the Antarctic in September 2025. The number is percent concentration. Sea Ice Today remains the public discussion of extent, which is the ocean area with at least 15 percent ice, set against a 1981-2010 median.

Why it is on this shelf

Surface temperature is a different measurement. Sea ice is frozen seawater. It reflects sunlight and follows its own calendar: the Arctic is near its maximum in March and its minimum in September, and the Antarctic is roughly the other way around. It is not glacier or ice-sheet mass on land.

How to read it

Lighter colour is higher concentration. Dark blue is open water or very little ice. Land is the NSIDC mask. Extent, the area above 15 percent, is a separate summary in the Sea Ice Index time series. Read the Arctic and Antarctic panels as two seasons, not as one global average.

Sources

Open source map →