Hail is ice formed like a ball or irregular lumps of ice that falls from the sky. Hail has caused over $1 billion dollars of damage. Most hail damage seen so far in Canada was in Saskatchewan. In July 28, 1981, a hailstone the size of a softball hit Calgary, Alberta,a causing about $150 million damage.

Hailstones on earth usually contain mostly water ice and measure between 5 and 105 millimeters in diameter. The largest hail stone ever is 17.8 centimeters which fell in Kansas, US. It was 5 ½ inches and weight 2 pounds. A hailstone can be 5-110 mm or pea-softball size.

Hail will form in the core of a thunderstorm, in thunder clouds called cumulonimbus clouds. Hail forms in the center of storm clouds when very cold water freezes. As a hailstone starts to form, it becomes too heavy for the cloud to hold and falls through the clouds, gathering more super cooled droplets as it falls.