How Much Does a Cloud Weigh? (Video) (IMAGE) American Chemical Society Caption Imagine 300 midsize cars floating above your head -- that's how much your average fluffy cloud weighs. So why doesn't it come crashing down on you? This week on Reactions, we explore the chemistry behind how a cloud stays aloft in the sky, and how it got there in the first place: https://youtu.be/a2GvzsaOncE. Credit The American Chemical Society Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.