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Every winter peak since 1979

Yes — each bar is one year’s Arctic winter maximum (highest extent in January–April). Recent lean winters show as orange and red.

— — Hover any bar to see that year’s winter maximum.

Blue = more winter ice vs 1981–1990; red = less. One bar per year.

Each square is one day in 2026. Red = less Arctic ice on that date than on the same date in any year since 1979.

new daily low for that date not a record

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Northern strip of the world map

Arctic · today

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Southern strip of the world map

Antarctic · today

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Loading the decadal trend…

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Jan–Apr peak

Arctic —

Antarctic —

Year with the most “lowest-ever for that date” days

Less reflective ice cover means more sunlight absorbed by the dark ocean — a feedback that speeds warming.
Arctic wildlife (including polar bears) depends on ice timing; hunting seasons have been shortening by roughly five days per decade in many regions.
A longer ice-free shipping season is opening the Arctic to new trade routes and geopolitical competition — even as coastal communities face more erosion and storm surge.

Pick a country to see how Arctic and Antarctic sea-ice change reaches it…

Ocean heat →Warmer water and air thin the ice from below and above.
Atmospheric warming →The Arctic is warming several times faster than the planet — the air-side driver.

Atlantic overturning circulation →Greenland and sea-ice meltwater freshen the North Atlantic, weakening the overturning current that delivers warmth to Europe.
Permafrost thaw →A darker, ice-free Arctic absorbs more sun, amplifying warming on land.
Sea level rise →The same warming that melts sea ice also melts land ice that raises seas.
Coastal flooding →An ice-free shoulder season exposes coastlines to autumn storms previously blocked by ice.
Tipping-point risk →Arctic summer sea ice is one of the 16 tipping elements scientists track.
Wildlife & shipping →Polar bears, seabirds, and ice-dependent marine mammals lose habitat; new trade routes open and reshape geopolitics.

Source: Daily sea-ice extent and the 1981–2010 reference climatology from the US National Snow and Ice Data Center (the Sea Ice Index, version 4), hosted on the US National Oceanic and Atmospheric Administration open-data servers.
Update cadence: Refreshed from the public daily files; numbers usually lag real time by about one day.
Methods: Ice "extent" is the ocean area with at least 15 % ice cover. Winter maximum is the highest Arctic extent in January–April each year. Record days are dates whose extent matches or undercuts the all-time low for that calendar date.
Limitations: Satellite sensors miss thin ice and melt ponds; day-to-day wiggles are normal. The multi-decade Arctic decline is robust. We do not average the poles — Arctic and Antarctic stories are deliberately shown side by side.
Read more: See the "About our sources" section on the Explained tab for the full data profile, or visit National Snow and Ice Data Center — Sea Ice Today and Arctic Report Card 2025 — Sea Ice essay for the upstream narrative.