In terms of diameter, the largest hailstone on record fell in Vivian, South Dakota, in the United States on 23 July 2010. The stone measured 8 inches (20.32 cm) across, which is similar to the size of a small bowling ball. It likely was even larger when it fell, however, because it is believed to have melted somewhat before it was measured. Previously, the largest hailstone on record was a stone that fell in Aurora, Nebraska, in 2003. That hailstone measured 7 inches (17.78 cm) in diameter.
More facts about hailstones:
- The cores of hailstones contain significant amounts of bacteria that are similar to the bacteria found in snowflakes.
- In the U.S. state of Colorado, the hailstorm season runs from March through October. The greatest concentration of storms usually occurs in June, with an average of 130 storms during that month.
- Hailstones can fall from a height of 30,000 feet (9,144 m) and approach the earth at speeds of as much as 120 miles per hour (193 km/h).
