A Cloud Can Weigh 1.1 Million Pounds. Here's Why It Floats
An ordinary cumulus cloud holds hundreds of tons of water. The numbers show why it stays up, and what has to change before it rains.
On a summer afternoon, a fair-weather cumulus cloud looks like it weighs nothing. It drifts, holds its shape and drags a soft shadow across the ground. Yet the U.S. Geological Survey estimates that an ordinary cloud of this kind holds about 1.1 million pounds of water. The usual explanation for why it doesn't come crashing down is that clouds are "lighter than air." That answer is only half right. The water in a cloud is far denser than air, and every droplet in it is falling. It falls so slowly, though, that the air rising beneath it wins.
By the Idle & Awake team · Oct 2, 2026 · 7 min read · Facts checked
