How much do clouds weigh?

The average cumulus cloud weighs 1.1 million pounds.

When people draw clouds, the results are usually big, fluffy, white creations, known scientifically as cumulus clouds. Although there are dozens of different cloud types, this is the one we most often associate with the word “cloud.” Though they may not be as mesmerizing as lenticular clouds hovering over volcanoes or as puzzling as arcus clouds stretching for miles, there still are some facets of them that truly boggle the mind. Take, for instance, the weight of an average cumulus cloud. Although these collections of water vapor seem to float effortlessly, clouds are extremely heavy. In fact, according to the United States Geological Survey, the average cumulus cloud weighs 1.1 million pounds.  If a cloud floats, how do you weigh it? Well, the U.S. National Center for Atmospheric Research estimates that the average cumulus cloud is about 1 kilometer (0.62 miles) long and 1 kilometer tall, or a billion cubic meters in volume. Meanwhile, the water density of a typical cumulus cloud is 0.5 grams (about a marble’s worth) per cubic meter. That means the average cumulus cloud holds 500,000,000 grams of water — or 1.1 million pounds. But while we have the equivalent of 100 elephants floating above our heads, the dryer, denser air beneath the cloud is even heavier, which is why those clouds can harmlessly float on by.