What weather phenomenon occurs when rain droplets freeze as they pass through below-freezing air?

The weather phenomenon that occurs when rain droplets freeze as they pass through below-freezing air is sleet. Sleet forms when raindrops fall through a layer of air that is below freezing, causing them to freeze into small ice pellets before reaching the ground. This process results in the formation of solid precipitation that can bounce when it hits the surface.

In contrast, hail is formed in thunderstorm environments where updrafts carry water droplets into extremely cold areas of the atmosphere, causing them to freeze into larger balls or irregular shapes before falling. Snow, on the other hand, consists of ice crystals that develop in clouds and fall to the ground when atmospheric conditions are cold enough throughout their descent. Freezing rain occurs when rain falls into a layer of cold air and improves its liquid form until it contacts a cold surface, causing it to freeze on contact rather than becoming solid before reaching the ground.