Hail Scale for Storm Spotters

A handy little app that displays a chart at 1:1 scale so that you can accurately measure hail stones according to the National Weather Service Standards. Includes all the latest recognized sizes for proper reporting of hail sizes.

No need to carry a ruler or other objects to photograph and record hail. Report accurately to the NWS and eliminates guessing. Use Rapid Report to photograph and upload your report to the NWS, Facebook and Twitter.

Sizes included in chart are:

0.25" (Pea) Size Hail

0.75" (Penny) Size Hail

0.88" (Nickel) Size Hail

1.00" (Quarter) Size Hail

1.25" (Half Dollar) Size Hail

1.50" (Walnut) Size Hail

1.75" (Golf Ball) Size Hail

2.00" (Hen Egg) Size Hail

2.50" (Tennis Ball) Size Hail

2.75" (Baseball) Size Hail

3.00" (Tea Cup) Size Hail

4.00" (Grapefruit) Size Hail

4.50" (Softball) Size Hail

Some users have reported inaccuracies in the ruler scales on the image.

To overcome this use the Calibrate Button in the upper left. Have a real ruler on hand for a one-time setup.

Your settings will be saved from each use so you don't have to redo the calibration each time.

If the ruler dimensions on the display are not matching up to a real ruler do the following:

1) Hold a ruler up to the scale and note if the image is larger or smaller than the ruler.

2) Press Calibrate

3) Pinch the image larger or smaller as needed.

4) Press Save

5) Check again with the ruler. If still off repeat steps 1 - 4