What is a cumulus cloud made out of?

Answer 1

as most of the what, 3 types of clouds are made up of dense, cold air & vaporized, suspended water molecules, I'd surmise that cumulus clouds are alike and are made of the same. They might have different characteristics, or they may be different especially in the eyes of a meteorologist, so consulting one of these pros could be essential in knowing EXACTLY what it is you're looking for in your answer.

When I fly, which used to be frequently, I almost always look out the planes' windows, and I love watching the wings mostly, only first to the clouds and cloud-cover. It's much like driving through the Blue Ridge Parkway or other mountain ridges at high altitudes, and seeing little or no real difference in those types of low clouds, fog, "mist", or other air-suspended precipitation, I'd say it's nearly the same, except some subtle differences.

When clouds of many types get too heavy and full of water vapor (which could be another way of saying what clouds are made of, I guess), then rain occurs. If the temperature is below freezing either in that part of the atmosphere, or in the lower parts, then things like hail, snow, freezing rain (dangerous on the groud, when driving, for example), & others will be what eventually makes it to the groud. But there's a chance that cumulus clouds could be actually made of a different type of water vapor, or the vapor has different properties, in which case the cloud's contents could be a bit different than simple water vapor/suspended water molecules.

I'm not a meteorologist nor am I anything but a college grad. So, this "answer" and subsequent writing is just something I sometimes like to do- answer to the best of my knowledge, especially if it's a question that's relatively easy for me, or intelligent and/or interesting. But, I still hope that it helped out.