sea ice · Arctic
Arctic Ocean (basin-wide)
September minimum sea-ice extent
Modelled demonstration series · not observed data
This is the most extreme tile on the wall and the least dramatic to look at, because the decline is so steady that no single year looks shocking. That is the trap. Measured against the baseline a person born in 1960 grew up with, the current minimum is not an anomaly at all — it is a different ocean.
75 years, modelled
Same reading, two normals
| Normal | Mean | σ | Pct | Return |
|---|---|---|---|---|
| 1951–1980 | 7.50 million km² | −8.60σ | <0.001th | 1 in 10^17 years |
| 1991–2020 | 5.81 million km² | −4.30σ | <0.001th | 1 in 120,000 years |
Today would be the lowest value in the entire 75-year modelled series. Past the series' standing low of 4.84 million km² (2022). Nothing about the reading changes between rows — only the yardstick.
Documented real-world record · well documented
3.39 million km² — September 2012
The National Snow and Ice Data Center recorded an Arctic September minimum extent of about 3.39 million km² — the lowest in the satellite record, which begins in 1979.
The season here
September is when Arctic ice reaches its annual minimum — the number that summarises how much survived the melt season.
Where this series comes from
MODELLED SERIES — not observed. Parameters set from published Arctic September minimum extent climatology and its documented decline of roughly 12 to 13 percent per decade since 1979. The 75 annual values are synthesised by the seeded generator. The real-world record cited separately is documented and is NOT part of this modelled series.
Every number on this page comes from a modelled series: 75 annual values synthesised by a seeded generator from published climatological parameters for Arctic Ocean (basin-wide). It shows how anomaly reasoning works. It is not a measurement and must not be cited as one.
How to read σ
σ counts standard deviations from this place's own normal. The sigma guide · return periods.
More sea ice stations
Open Arctic Ocean (basin-wide) on the field →