World Climate Lab Honest weather for invented worlds

Nothing here chases you. There are no timers, no fail states, no score: just you, a planet and a few spare minutes. Pick a world, nudge its spin or thicken its air, and watch the climate find its balance over a couple of minutes while the Energy Flow view quietly reports whether the planet is settling, still cooling, or running away. It is the rare simulation you can lean back and simply observe, one small change at a time, at whatever pace the evening allows.

A map you have drawn is more than a picture here. Upload a heightmap, any size, and 16-bit files keep every gentle slope; draw a sea mask to place your coastlines exactly, or slide the sea level up and down with one control. A depressions mask keeps basins dry below sea level, so a cut-off inland sea gets dense, warm air and rivers that end where the water runs out. Add a sea floor map and the tides follow it, piling up in shelf seas. Earth itself comes with its real coastlines and real sea floor.

The Topography Creator is a full terrain editor built into the game. Start from a blank ocean or generate a world of drifting plates, then shape the globe with 73 brushes, stencils and a library of ready-made landmasses.