Hello how may I help you? iwant to fin out about world records Ok sure I have a lot of information on World Records for you! What is the worlds biggest cloud? I'm sorry. I am not sure what you mean by that question. Could you please verify if you meant tallest, widest, heaviest? Widest please Ok did you mean cirrus cloud, cumulus cloud, (...) Cirrus cloud The largest cloud was found in the Amazon River basin of Brazil. It spanned 50 km by 40 km! How big was it? Thank you You are very welcome!