Clouds, which appear soft and weightless, can actually weigh up to a million tonnes. This surprising weight comes from the billions of tiny water droplets or ice crystals that make up a cloud. For instance, a typical cumulus cloud, measuring about one cubic kilometre, can contain hundreds of tonnes of water. The reason clouds float is not due to their lightness but because they are less dense than the surrounding air. The warm air inside clouds rises, allowing the tiny water droplets to remain suspended. Additionally, continuous updrafts in the atmosphere help keep these droplets aloft. However, when the droplets combine and grow larger, they can become too heavy for the air currents to support, resulting in precipitation. This fascinating interplay of physics explains why clouds, despite their significant weight, remain floating above us.