Hail size chart
This chart shows the National Weather Service reference objects for estimating hail diameter, from pea to grapefruit. Hail of 1.00 inch, about the size of a quarter, is the severe threshold and triggers a Severe thunderstorm warning. The widest hailstone on record in the U.S. measured 8.00 inches in Vivian, South Dakota, on July 23, 2010.
Right nowKp 0.67as of 3:08 PM EDTSee every state
The chart
| Object | Diameter (inches) | Severe? |
|---|---|---|
| Pea | 0.25 | No |
| Marble or mothball | 0.50 | No |
| Penny | 0.75 | No |
| Nickel | 0.88 | No |
| Quarter | 1.00 | Yes |
| Half dollar | 1.25 | Yes |
| Ping pong ball | 1.50 | Yes |
| Golf ball | 1.75 | Yes |
| Hen egg | 2.00 | Yes |
| Tennis ball | 2.50 | Yes |
| Baseball | 2.75 | Yes |
| Tea cup | 3.00 | Yes |
| Softball | 4.00 | Yes |
| Grapefruit | 4.50 | Yes |
How sizes are reported
The widest diameter of the largest stone found, in inches, is what spotters report. A ruler provides a more accurate measurement than comparing to objects, and each report is flagged as either measured or estimated. WeatherTotals posts the reported sizes as they arrive on the hail reports by state page.
What the sizes mean for warnings
- 1.00 inch (quarter) or larger: the National Weather Service issues a Severe thunderstorm warning.
- 1.75 inches (golf ball) or larger: the warning is tagged as considerable.
- 2.75 inches (baseball) or larger: the warning is tagged as destructive and triggers a phone alert.