It's interesting to know!

Where the clouds are when the sky is quite clear?

We know that clouds are made of water, and water can exist in the air in many different forms. When the water forms a cloud, it is in the form of drops which form a cloud from our breath on a cold winter day. There is water in the sky when it is quite clear. How can it be? The thing is that the air is able to hold all the water in the form of a gas. It is difficult for us to realize when we look up at the sky on a fine day that we are looking through water. So we can say that water forms part of the air, and a very useful part, too. If there were no water in the air, the heat of the sun would scorch us.

Does a cloud weigh anything?

When we see a cloud floating in the sky, we think that it has no weight. We often say 'as light as a cloud' when we want to describe anything very light indeed. But a cloud has weight, because it consists of drops of water, and a large cloud may weigh tons. You may ask why, if a cloud is heavy, it floats and doesn't fall. The answer is that a cloud only seems to float and that all the time the little drops of water in it are slowly falling. The clouds seem still because new drops of water condense and replace the falling drops, which often evaporate when they fall, and never reach the ground.