Hail is a form of solid precipitation. It consists of balls or irregular lumps of ice, each of which is referred to as a hailstone. Unlike graupel, which is made of rime, and ice pellets, which are smaller and translucent, hailstones – on Earth – consist mostly of water ice and measure between 5 and 200 millimetres (and in) in diameter. The METAR reporting code for hail 5 mm or greater is GR, while smaller hailstones and graupel are coded GS.
