Sizes at a glance
| Diameter | Compared to |
|---|---|
| 0.75 in | Penny |
| 0.88 in | Nickel |
| 1.00 in | Quarter |
| 1.25 in | Half dollar |
| 1.50 in | Ping pong ball |
| 1.75 in | Golf ball |
| 2.00 in | Hen egg |
| 2.50 in | Tennis ball |
| 2.75 in | Baseball |
| 3.00 in | Teacup |
| 4.00 in | Softball |
| 4.50 in | Grapefruit |
When hail counts as severe
The National Weather Service calls a thunderstorm severe when it produces hail 1 inch in diameter (quarter size) or larger, or winds of 58 mph or more. NOAA's final records include hail from 0.75 inch; daily reports and Aeonis Storm start at 1 inch.
Which sizes damage roofs
There's no single threshold. Hail around 1 inch can damage older or brittle asphalt shingles, gutters and soft metals; 1.75 inches (golf ball) and larger often damages newer roofs, siding and cars. Wind-driven hail does more damage than hail falling straight down, and roof age and material matter a lot.
How sizes are measured
Spotters measure the largest stones they find, or compare them with common objects. That's why so many reports are exactly 1.00 or 1.75 inches: quarters and golf balls are easy comparisons.
Reports are points, not swaths
A report tells you the size at one spot. The same storm can drop larger or smaller hail a mile away. Use reports to find dates and likely areas, then inspect.