EARTH / ICE

Arctic sea ice: seasonal contours

Ice expands and retreats across the Arctic Ocean. Follow the shapes of the seasons through 12 months of satellite observations.

September 2025–August 2026
25 km grid / monthly means

Mean ocean sea ice concentration23.6%Mean of 26,939 common valid ocean cells north of 60°N

Sea ice concentration % · Linear scale

050100and above

■ Land · Navy: ocean · White: high ice concentration

Missing / outside ocean coverage

100 %and above use the maximum color. Source values are unchanged.
Detections at the color ceiling:0 cells

Polar stereographic projection · Drag to pan

Base layers

Basemap

Choose a terrain style, then add boundaries and place names.

Map overlays

Relief shading is derived from elevation and water depth. More detail loads as you zoom in. State borders and city names appear at readable scales.

Basemap sources & guide

NOAA ETOPO 2022 ↗: Elevation and depth at 60 arc-seconds. Contour intervals change with zoom: 2,000 / 1,000 / 500 / 200 m. Seafloor relief includes depth contours. Terrain shading is enhanced while data shading stays subtle. Elevations are not extruded in 3D.

Natural Earth 1:10m ↗: Coastlines, administrative boundaries and place names. Borders follow the source's de facto representation; disputed or undetermined boundaries are dashed. Place names follow the selected language where available.

Loading basemap detail…

Preparing the map and full timeline
Once ready, playback needs no further downloads

Select the map to read source values

All three views share the displayed time and selected location.Spatial and temporal interpolation creates neither new observations nor fine-scale vortices.

Monthly means · 12 months

2025-09

1 / 12

Artwork edition ↗Preparing · Fixed period

Interpolated change between monthly means, not daily observations.

ICE / Seasonal contours

A year of expansion and retreat.

From navy ocean to white ice: read monthly mean ice concentration on a 25 km grid from September 2025 to August 2026.

Start exploring

Compare winter expansion and summer retreat from the same viewpoint. Select a location to check color differences numerically.

What this visualization shows

Transitions between months are display interpolation. They do not show daily ice motion or a long-term decline rate.

How to read this map

Sea ice concentration is the share of each 25 km cell covered by ice, not thickness.

Values are grid means over ocean north of 60°N that is valid in all 12 months. Not sea ice area or extent.

添えています。斜線は海域の欠測・対象外で、海氷0%とは区別します。長期減少や過去の最小記録との比較は含みません。別の色で示し、海岸線陸・海・氷

The display spatially interpolates values. Playback interpolates adjacent time steps without filling missing gaps. Source-grid and displayed values can be inspected separately.

Interpolated transitions between monthly means, not daily sea ice observations.

The sea ice scale remains fixed; land, ocean and space outside the globe use distinguishable backgrounds.

Select the map to inspect source values. Zooming magnifies the display without changing observation resolution.

Sources & this visualization

Meier, W. N., Fetterer, F., Windnagel, A. K., Stewart, J. S. & Stafford, T. (2026). NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration, Version 6. doi:10.7265/b18j-z797. Northern Hemisphere, monthly, Sep 2025–Aug 2026. Accessed 2026-09-20.

Made with Natural Earth (v5.1.2; tiled basemap 1:10m, archived releases 1:50m).

Official data guide ↗

Source, processing & release record ↗

Web rendering & enhancement settings ↗

SORAH Design System 1.6.0 / Foundations 6.3.0. Phenomenon palette: Earth Language 1.0.0 is retained. Both 3D and 2D interpolate source values before applying colors.