Question

Why are falling rain drops spherical?

Answer 1

Raindrops start to form in a roughly spherical structure due to the surface tension of water. This surface tension is the "skin" of a body of water that makes the molecules stick together. The cause is the weak hydrogen bonds that occur between water molecules.

Answer 2

The shape of a drop of rain is constrained by the surface tension, which tries to give it the shape for which the surface area is minimum. For a given volume, the spherical shape has the minimum surface area. That is why rain drops acquire spherical shape.