A hailstone is a small ball of ice that falls from the sky during thunderstorms. You can see them bouncing along the ground when they hit.
When it's storming outside and there are big claps of thunder, people might get out their phones to record some amazing sights – like a small hailstone falling onto the pavement or into a puddle. That's because these tiny balls of ice are really cool (no pun intended!). They're also known as "ice pellets" in some parts of the world. In science class, you might learn about how hailstones form inside thunderstorms when water droplets get swept up into big air currents and freeze into solid balls.
A single ball of hail, or solid precipitation
