Hail Storming

The largest recorded hailstorm in terms of hailstone size and damage occurred in Vivian, South Dakota, on July 23, 2010, when a hailstone measuring 8 inches (20.3 cm) in diameter, 18.62 inches (47.3 cm) in circumference, and weighing nearly 2 pounds (0.88 kg) was recovered—officially the largest hailstone ever documented in the U.S. by the National Weather Service.

This supercell-produced storm not only shattered size records but also caused widespread destruction to vehicles, roofs, crops, and infrastructure, with some hailstones punching through roofs and breaking house windows.

The hailstone’s immense size was the result of prolonged suspension in an updraft exceeding 100 mph (160 km/h), allowing successive layers of supercooled water to freeze around a core.

It was preserved in a freezer by the discoverer and later verified for size and weight by NOAA, offering a rare opportunity to study extreme hail formation dynamics in severe convective systems.