Question

why hail stones are falling?

Answer 1

hails stones are falling because of decrease in temperature of atmosphere this leads to freezing of clouds so hails are falling

Answer 2

Hail forms when thunderstorm updrafts are strong enough to carry water droplets well above the freezing level. This freezing process forms ahailstone, which can grow as additional water freezes onto it. Eventually, the hailstone becomes too heavy for the updrafts to support it and it falls to the ground.