Hail Records
Largest Hailstone Records: How Giant Hail Forms and Gets Measured
How giant hail forms inside supercell thunderstorms, how hailstones are measured, and why official records need careful documentation.
Quick answer: The largest hailstones form in powerful thunderstorms with strong updrafts that keep ice growing before it falls.
Growth process
Hail grows as ice cycles through regions of supercooled water inside a storm.
Strong updrafts can support larger stones before gravity wins.
Measuring hail
Record hailstones are documented by diameter, circumference, weight, photos, and sometimes official examination.
Melting begins quickly, so timing matters.
Safety
Giant hail can break windows, damage roofs, injure people, and total vehicles.
Move indoors and away from glass during severe hail warnings.