Can a cloud weigh as much as a 747?

The maximum takeoff gross weight of a 747 is 875,000 pounds. Did you know this includes six million parts? Three million of which are fasteners? One and a half million of which are rivets? The people at Boeing are full of fascinating facts like this.

Anyway, let's be scientific and say a 747 weighs 400,000 kilograms. The amount of water vapor in clouds varies widely depending on temperature, pressure, etc., but five grams per cubic meter is about average.

A good sized cumulonimbus cloud, or thunderhead, might be ten kilometers tall, with a base ten kilometers in diameter. Noodling a bit, we come up with a volume of 785 billion cubic meters per cloud (you can see this is not looking good). This gives us a mass of roughly four billion kilograms per cloud, or the equivalent of not one but 10,000 747s.

To put it another way, a modest-size cloud, one kilometer in diameter and 100 meters thick, has a mass equivalent to one 747.