Arctic Ice

The area covered by Arctic sea ice

The graph shows the average of the “Area of Arctic Sea Ice during September” each year.
The area shown is in millions of square kilometres.
The yearly “September extent” is relevant because the area covered by Arctic sea ice reaches a minimum during September. The area increases during winter and decreases in summer.

The average September extent of Arctic Sea Ice is declining by 13.7% per decade relative to the 1979 to 2000 average.

The latest graphs of sea ice extent show the decline continues.
See the latest Arctic Sea Ice graph.

On this page:

Arctic ice reflects light, cooling the Earth

“Arctic ice plays an important role in maintaining the Earth’s temperature. The shiny white ice reflects light and heat that the ocean would otherwise absorb, keeping the Northern Hemisphere cool.”
(US National Snow and Ice Data Centre: NSIDC)

Warming of the Arctic is causing further warming

A dangerous spiral is becoming established in the Arctic: the Arctic’s warming is causing further warming.

Higher global temperatures		Less ice cover

*		Less sunlight is reflected into space & more absorbed.

In this amplifying feedback cycle:

higher global temperatures tend to cause
reduced areas of highly reflective ice, which tend to cause
less reflection of sunlight back into outer space, which tends to cause
more absorption of sunlight, which tends to cause
higher global temperatures.

Note that this feedback can run in reverse, with “lower global temperatures” leading to “more sea ice”, leading to “the reflection of more sunlight”, leading to “lower temperatures” – but first you would need lower global temperatures.

The Arctic is warming fast

The Arctic has warmed twice as fast as the rest of the globe.
Our nurturing climate is at risk: The Arctic sea ice is decreasing by 13.7% per decade.

Arctic Sea Ice Area: Daily graph

See the latest daily ice cover changes over the current calendar year – and compare this to previous years on the “US National Snow and Ice Data Centre” (NSIDC) web page.
http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

Here is a photo of this interactive web page on 6 April 2015.
You can click on the graph to enlarge it.

The graph shows “Arctic Sea Ice Extent”: the area with more than 15% sea ice, measured in “millions of square kilometres”.
The dotted green line shows the sea ice area for each day of the record-low year of 2012. You can see that the ice area was greatest in mid-March 2012. It was lowest in mid-September.
The blue line from 1 January to 5 April shows the ice cover for 2015. The 2015 line ends on 5 April, as I took the photo on 6 April.
The thick black line is the average extent for each calendar day from 1981 to 2010
The grey area on the graph shows two standard deviations on each side of the average.
This NSIDC web page is interactive; e.g., you can click any year in the list on the right of the page to see how ice cover moved that year.

References

A regime shift is taking place as the Arctic sea ice melts (ABC: 13 Jan 2021)

Arctic sea-ice loss accelerates Arctic warming: Scientific American: 2010

Updated 28 March 2022 and 10 Jan 2026