The hail is a type of showers in the form of particles of ice of mainly roundish form. The structure and the sizes of hailstones differ in a big variety. Hailstones consist of layers of transparent ice not less than 1 mm thick. The hail drops out, as a rule, in a warm season of a powerful cumulonimbus clouds, usually at heavy rains and thunder-storms. The hail drops out usually in the afternoon. A night hail is a very rare phenomenon. The phenomenon of a hail is followed by special characteristic noise from collisions of hailstones. Hailstones are formed in the overcooled cloud due to casual freezing of separate drops. Further they can grow to considerable sizes because of icing of facing drops.