Clouds are formed by a visible amount of snow-covered air or microscopic water droplets in the atmosphere. There are several types depending on height, shape and evolution. In function of these variables the amount of water contained in each of them may range from several milligrams to several grams per cubic meter of air.
Since H2O molecules are lighter than oxygen and nitrogen in the atmosphere, the average wet air density is less than that of dry air. At sea level, this parameter is about 1.2 kg / m 3 in wet air and 1.225 kg / m 3 in dry air. As a consequence of Archimedes' principle, wet air masses climb to the highest layers of the atmosphere.
Steam height is transformed into micro-organisms or ice crystals, but the density remains small compared to the surrounding air. That is why clouds remain at the same height. In terms of weight they are great when they are voluminous. Classical clouds are good-looking white aggregates with an average of 1 gram of air per cubic meter and weighing hundreds of tons. Storm collections contain hundreds of thousands of tons of water.