Believe it or not But It’s True 1 . Clouds Float But They Are Very Heavy We might think that clouds are floating in the air so they must be pretty light . But it’s not so, on the contrary they are very heavy . They look fluffy and very light because they are swimming with ease in the air . Researchers have observed that an average cumulus cloud (Heap, here means cloud forming masses heaped together at low altitude ) , which is the very nice fluffy white we see on a sunny day , weighs 500 metric