WebGCM

A global climate model that runs in your browser.

The Americas seen from space, with cloud over the Caribbean and the Amazon and the sunglint in the eastern Pacific Europe and Africa seen from space, with the Sahara, the Mediterranean and the rain clouds of the Congo basin Asia seen from space, from Siberia to the cloud over the Maritime Continent and northern Australia A close view of the day–night terminator crossing the Pacific, the sunlit clouds reddening toward the night side and the blue twilight along the limb Antarctica and the Southern Ocean seen from above the pole, half lit by a sun on the horizon, with the sea ice and the storms around the continent A world map of surface wind speed, with the storm tracks of both hemispheres in green and red and the trade winds in blue Wind speed at 250 hPa with height contours, the polar jet crossing the Atlantic into Europe A close view of surface wind speed, isobars and wind arrows circling a storm in the Gulf of Alaska A world map of surface temperature centered on the Pacific, with isobars and wind particles A world map of total precipitable water, with the moist tropics in yellow and plumes of moisture reaching into the midlatitudes Rising and sinking air at 500 hPa over the North Atlantic, red where the fronts of a storm south of Greenland lift the air and blue where it sinks behind them A world map of outgoing longwave radiation, dark where tall cloud reaches the cold upper troposphere and bright over the deserts Snow on land across Canada, Greenland and Siberia at the end of winter, seen from above the North Atlantic A world map of vegetation cover, dense in the rainforests and the temperate forests and bare in the deserts Ocean current speed off North America, with the Gulf Stream leaving the Gulf of Mexico and meandering out into the Atlantic Ocean current speed south of Japan, with the Kuroshio running from Taiwan along the Japanese coast and out into the Pacific A world map of sea surface temperature, warm across the tropics and cold around the poles, with particles tracing the surface currents Current speed at 150 m depth along the equatorial Pacific, with the undercurrent flowing east beneath the trade winds Mixed layer depth over the North Atlantic in March, with the deep mixing of the Labrador and Irminger Seas Ocean current speed off the coast of Brazil and the Guianas, with the North Brazil Current running northwest along the coast toward the Caribbean

Climate model

A global climate model running live: a hydrostatic atmosphere with 36 layers on a geodesic C-grid, moist convection and clouds, a 45-layer ocean with a mixed layer over 44 isopycnal layers, sea ice, snow, soil and vegetation on real continents with terrain. Every kernel runs on the graphics card through WebGPU. It picks up from day 1825, the March equinox at the end of a five-year spin-up, at up to 128 subdivisions on a desktop, about 164,000 cells 56 km across, or up to 64 on phones and tablets, about 41,000 cells 112 km across; the first time the page opens, a quick test picks the engine and the finest resolution your device runs well. You can color the globe by wind, temperature, pressure, rain, clouds, ice or ocean currents, draw isobars, follow the wind with particles or arrows, watch the planet from space, and save snapshots.

Best in a browser with WebGPU (Chrome, Edge or Safari 26). Without it the model falls back to a slower CPU engine. The starting state is a 244 MB download on a desktop and 62 MB on phones and tablets, kept in the browser after the first visit.

Open the climate model →
The model's state drawn in 3D: six layers of hexagonal cells, warmer in potential temperature higher up, with an arrow across every edge for the wind

How WebGCM works

An illustrated explainer with live figures you can push on, building the model up from a single parcel of air: heating and lifting it, setting the planet spinning, covering a sphere with a grid, the primitive equations taken apart term by term, a dry atmosphere that makes its own jet streams and storms, a planet warmed by the real sun, the water that evaporates from its sea, condenses into cloud and rains, and the sea itself, which stores heat, is pushed by the wind into currents and freezes at the poles.

Start with part 1 →
A geodesic polyhedron shaded by procedural terrain

Geodesic grid

Where the project began, and where its repository got its name: an icosahedron subdivided into 100,002 cells, all hexagons but twelve pentagons, shaded by procedural terrain and rendered with Three.js. Drag to rotate, scroll to zoom.

View the grid →
A 500 hPa chart with geopotential height contours over wind speed

Synoptic charts

Weather-map plots drawn from saved model states: geopotential height contours and wind speed at standard pressure levels on an Equal Earth projection, downloadable as SVG or PNG.

Draw a chart →