Hail

weather · ice · storms · nature

Balls of ice. Hail forms when raindrops get swept up into the freezing top of a thunderstorm cloud, where they freeze solid. These frozen drops bump into other drops, which freeze onto them, building up layer after layer like an onion.

Needs warm weather. Hail actually forms best when the ground is warm but the high clouds are super cold. That temperature difference creates the powerful updrafts that keep ice balls floating high in the clouds long enough to grow big.

Different from sleet. People often mix up hail and ice pellets (sleet), but they're different. Hail forms in the cold upper clouds, while ice pellets form when rain falls through a thin cold layer near the ground.

Falls really fast. When hailstones finally get too heavy to float, they drop, sometimes at speeds over 100 miles per hour! That's why hail can dent cars and damage crops.

Sizes vary wildly. Hailstones can be tiny like peas or huge like baseballs. The biggest ones grow in the strongest thunderstorms where powerful winds keep them bouncing around for longer.