Hailstorms are a product of severe thunderstorms. Hail is formed when strong updrafts within the storm carry water droplets above the freezing level, where they remain suspended and continue to grow larger, until their weight can no longer be supported by the winds. Hailstones can vary in size, depending on the strength of the updraft.
The National Weather Service (NWS) uses the following descriptions when estimating hail sizes:
| Pea size is ¼-inch | Quarter size is 1-inch |
| Marble size is ½-inch | Golf ball size is 1 ¾-inches |
| Dime size is ¾-inch | Baseball size is 2 ¾-inches |
Individuals who serve as volunteer "storm spotters" for the NWS are located throughout the state, and are instructed to report hail dime size hail (¾-inch) or greater. Hailstorms can occur throughout the year, however, the months of maximum hailstorm frequency are typically between May and August. Although hailstorms rarely cause injury or loss of life, they can cause significant damage to property.