Largest hailstone found in USA (South Dakota). It weighed nearly two pounds. Public Domain Image

Hail is large ice particles formed during violent thunderstorms. During a strong thunderstorm, water droplets are violently lifted high up into the cool atmosphere where they change to ice. The faster this “updraft” occurs, the larger the hail stones (as they are called) can be. A typical hailstone is the size of a marble or a pea, but sometimes they can be the sizes of baseballs and softballs where they cause significant damage (see video below). The largest hailstone ever recorded weighed 1.93 pounds. It fell in South Dakota in 2010.

Video of Hailstorm in Woodward, Oklahoma


Sleet is defined as frozen raindrops that bounce upon impact with the ground. Sleet can only form from snow. When the snow falls from the sky and through a layer of warmer air, it partially melts. As it falls, the partially melted snow then re-enters cold air and re-freezes forming an ice pellet.

Freezing Rain

Freezing Rain occurs when liquid rain falls and freezes upon contact with the ground because of ground temperatures below freezing. Freezing rain causes dangerous conditions for drivers when it accumulates on roads as drivers can easily lose control of vehicles, especially when trying to brake or slow down Freezing rain can also accumulate on and down trees and telephone wires.