Why are humidity and clouds different? Why is one invisible while the other isn’t? And why would humidity not clump together like clouds do?

Question

Why are humidity and clouds different? Why is one invisible while the other isn’t? And why would humidity not clump together like clouds do?

In: 9

Answer 1

Humidity needs nucleation sites to accumulate enough to be visible. Essentially, little bits of dust that the humidity can condense on to form large enough droplets to scatter light, but still small enough to float.