Type of Cloud Is Associated with Hail

The type of cloud most often associated with hail is the cumulonimbus cloud. These are large, towering clouds that form during strong thunderstorms. Cumulonimbus clouds can grow very tall—sometimes reaching over 10 miles (16 kilometers) into the sky—and stretch through different layers of the atmosphere.

Hail forms inside these powerful clouds when updrafts (strong upward winds) carry water droplets high into the cold parts of the cloud. The droplets freeze into small pieces of ice. As they are lifted up and down by the wind, more layers of ice build up around them. Once the hailstones become too heavy for the updrafts to hold, they fall to the ground.

Cumulonimbus clouds are also responsible for producing lightning, thunder, heavy rain, and even tornadoes. These clouds need warm, moist air at the surface and cooler air above to form. The strong rising air inside them creates the perfect conditions for severe weather.

Hail can damage crops, cars, and buildings, especially when the stones are large. That’s why weather forecasters watch cumulonimbus clouds closely during thunderstorms.

Fun Fact: The largest hailstone ever recorded in the U.S. was nearly 8 inches wide—about the size of a volleyball!