With the severe weather and hail we’ve had this summer, people often ask “How big can the hail get?” For a long time, Kansas had the record. On September 3, 1970 Coffeyville Kansas was pounded by the largest hailstone on record. This stone measured 5.7 inches in diameter, 17.5 inches in circumference and weighed 1.67 pounds. On June 22, 2003, Nebraska set a new record when a hailstone 6.5 inches in diameter fell on Aurora. The circumference and weight was slightly less than the Coffeyville stone, but it is still considered the new record for largest hailstone. Still the record was short lived. On July 23, 2010 a new record setting hailstone was discovered in Vivian, SD. Measurements: 8.0 inches in diameter, 18.625 inches in circumference, and weighing an amazing 1.9375 pounds!
Mary Knapp, Weather Data Library