Hail sizes from pea to softball, and how to measure one

The chart

Where your stone falls between two objects the checker lists, pick the smaller one. That mirrors the measuring guidance from NOAA's State Climate Extremes Committee, which says to record the lower increment when a stone falls between marks.

Two warning sizes to remember

The NWS moved its severe hail line from penny size to quarter size on January 5, 2010. Warnings also carry damage threat tags: considerable from 1.75-inch, golf-ball hail and destructive from 2.75-inch, baseball hail. The Chicago office adds that only about 10% of severe thunderstorms reach the destructive category nationwide in an average year.

Charts do not always agree

Object charts vary a little from office to office. The Baltimore/Washington NWS office's SKYWARN chart lists 4 inches as grapefruit size and 4 1/2 inches as softball size, the reverse of SPC's table, which puts softball at 4.00 inches and grapefruit at 4.50. The committee's guide also discourages objects of widely variable size, such as marbles and walnuts, for reporting. SPC's own table says it encourages measurement rather than estimation.

How to measure a hailstone safely

The State Climate Extremes Committee's hail standards, published by NOAA's National Centers for Environmental Information, set out a simple sequence:

1. Never go out for a hailstone until it is safe to do so.
2. Photograph the stone where it lies, with a ruler or an object of known size beside it.
3. Pick it up with gloves, a towel or tongs, so your hand does not melt it.
4. Measure the widest part: set the stone on a flat surface, stand a box or brick against each end, and measure the gap with a ruler marked to at least 1/8 inch.
5. If a scale is handy, weigh it, and measure the circumference with a flexible tape or a length of string.
6. Seal the stone alone in a clear plastic bag, put it in the freezer, and report it to your local NWS office.

The NWS and CoCoRaHS reporting sheet puts it more simply: once the storm has passed and it is safe, use a ruler to measure the largest, smallest and average stones. The Boise office's shorthand for a very large stone is to freeze it, measure it and notify the NWS.

What size means for a roof

The NWS Melbourne office says storms with hailstones the size of quarters or larger can damage roofs, dent cars and break windows, and that large hailstones can fall faster than 100 mph. For the tougher end of the scale, IBHS says shingles rated Good or Excellent in its hail ratings better protect a home from hail up to 2 inches in diameter. NRD's encyclopedia explains the Class 4 impact-resistant shingle rating you will see on product labels.

Where big hail falls most

These counts from NOAA's Storm Events Database cover 2016 through 2025, counting events by county:

NOAA's Storm Events Database records more than 11,000 hail events of 1 inch or larger in Texas over that decade, the most of any state in the set. Wherever you live, the NRD Storm Center has a page for your state, and the documenting roof damage guide covers what to record after a hailstorm.

Frequently asked questions

Is quarter-size hail severe?

Yes. The NWS severe criterion is hail at least 1 inch in diameter, and a quarter is the 1-inch object on SPC's table.

My hail was between two sizes. Which should I choose?

Choose the smaller one, as the SCEC measuring guidance does when a stone falls between marks. If you ticked any damage signs, the checker will still send you to an inspection.

Should I keep a big hailstone?

Yes, if it is safe to collect. The committee's guidance is to seal it alone in a plastic bag and freeze it as soon as possible, then call your local NWS office.