Why does a ball fly better in dry air?

Answer 1

Mostly the air you breathe has some water in it. Air with a bigger humidity is thicker. Not that you would notice it while walking or anything like that. So if you throw a ball in to water, it's not going to go very far, but when you throw it in the air, it flies much further. So the less there is water in the air, the less air resistance there is to slow the ball down.