As the title asks, what is the average mass of each kind of cloud?
Ignoring things like overcast days, and only considering clouds large enough to identify. Or maybe rather than "average" it'd be better to say "what is the mass of an archiypical cloud of each type?" Eg an archiypical cumulus, cirrus, cumulonimbus, etc.
Researchers at the US National Centre for Atmospheric Research calculated the density of a cumulus cloud to be around 0.5 grams (0.018 ounces) of water per cubic meter, so a 1 cubic kilometer (0.24 cubic mile) wide cloud would contain 1 billion cubic meters (35 million cubic feet). If you calculate the number of cubic meters times by the density, 1,000,000,000 x 0.5, you’ll be left with the total weight of a cumulus cloud of that size – 500,000 kilograms (1.1 million pounds).