Clouds are made of tiny water droplets or ice crystals floating high above the ground.

The longer version

Water vapor in rising air cools until it can no longer stay a gas, so it condenses onto microscopic specks of dust, salt, or smoke. Each speck collects a thin film of water, and billions of them together form what we see from below as a cloud. The colder upper parts of a cloud hold ice instead of liquid.

The droplets are so small and light that gentle upward air currents keep them suspended. They become visible as a distinct shape only where the air has cooled enough for condensation to begin. That boundary marks the cloud base, and its height depends on how moist and how warm the air beneath happens to be.

Where this entry sits

Clouds, wind, rain, and storms shape daily life in ways that most people barely notice. This collection explains snow, lightning, rainbows, the turning seasons, temperature, the instruments forecasters rely on, and scraps of old weather lore. The full list sits on the Weather and Climate page, where every entry is listed in order.