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.
At sea level air is about 1.25 kg/m³, so for one cubic kilometer cloud that is :
1 250 000 tons.
I put your result into table
to show a problem at 51 km and above… since density decreases monotically with altitude.