Arctic sea ice minimum
4.75M km²as of 2025
The Arctic's September sea-ice minimum has shrunk to about 4.75 million km² (2025) — down from around 7.05 million km² in 1979.
Source: NSIDC Sea Ice Index, via Our World in Data. Data through 2025. Download the data (JSON).
About this indicator
Each September the floating ice cap on the Arctic Ocean reaches its yearly minimum, after melting through the summer. Satellites have measured this minimum extent since 1979.
The trend is a steep, long-term decline: the Arctic is warming several times faster than the global average, and its late-summer ice has lost roughly a third of its area over the record.
Why it matters: Losing bright sea ice exposes dark ocean that absorbs more heat, accelerating Arctic warming and disrupting weather far to the south.