How far away a hail report can be and still count
Distance is a property of the pair
A hail report has a location. A spotter stood somewhere and measured a stone; a cooperative observer filed from a back yard; a radar algorithm computed a size for one cell of a grid. The federal record files each of those at a point, with a time, and that point is the whole of what the record says about where the hail was. A property has a location too. The distance between the two is not a property of the report and not a property of the property. It belongs to the pair, and it changes every time the pair does.
The same measured stone is close evidence for the roof it fell beside and distant evidence for one across the county, and neither reading is wrong. A report for an address states the distance and the bearing from the roof to every report it cites, because a figure without those two is a figure about somewhere else. The bearing matters as much as the distance: a storm moves, and a report to the southwest of a roof on a day the cells tracked northeast is a report from upstream of it.
What a distance can establish is that hail was on the ground, measured, at a stated place and time that near. What it cannot establish, at any distance, is that hail reached the roof. The record attests occurrence, date and place; the inference from a point to a roof is the reader's, and the report leaves it to the reader.
The relevance bands
The report does not leave the reader to judge every distance from nothing. It bands them, the same way for every address and every storm, and it states the bands in its own method section so the reader can disagree with the bands rather than with a figure.
| Band | Distance from the address | What it says |
|---|---|---|
| Primary | within 3 miles | Close enough that the report treats it as evidence about the storm at the property. |
| Contributing | within 10 miles | Evidence that the storm was in the area on the day, read beside the primary reports rather than instead of them. |
| On record | beyond 10 miles | Part of the day's record, and cited as such where the report lists the day; not offered as evidence about the property. |
A primary report is one filed within 3 miles of the address. That is roughly the reach of one storm cell's hail core as it passes, and it is the band inside which the report will say that hail of a stated size was measured near the property on the date. A contributing report is one filed within 10 miles. It does not say the hail reached the roof; it says the storm that produced measured hail was in the area that day, which is the question a reader asks of a primary report before trusting it.
The bands are applied to measured and detected reports alike, and the report keeps the two apart inside each band. A radar-derived size within the primary band is still a detection rather than a measurement: it is drawn as a hollow mark, set in the estimated tone, qualified as analyzed, and never added to a measured size to make a larger one. A measured stone in the contributing band outranks a radar-derived size in the primary band as evidence that hail fell, and ranks below it as evidence about this roof, and the document lets the reader see both orderings at once rather than choosing one.
Nothing about the bands is an opinion about damage. A report inside the primary band establishes that hail of that size was measured there, then. What it did to the roof is the inspection's to say.
A swath is wide, and a county is not a point
Hail does not fall at a point. A storm lays it down in a swath: a band a few miles across and much longer than it is wide, running the direction the cell moved, with the largest stones in a narrower core and smaller ones along the edges. A measured report is one place on that swath where someone happened to be standing. The absence of a report at the roof says nothing about the swath's width; it says nobody filed from the roof.
This is what a radar-derived size is for. Radar covers the ground nobody reported from, and the swath the report draws on its map is drawn from radar. It is the only kind of evidence that can say the storm's hail signature passed over the property itself. It is also an estimate of what the storm was capable of, not a record of what fell, which is why the map labels it as a detection and the document never prints it as a measurement. Read together, a measured stone a short distance along the swath and a detection over the roof say more than either does alone, and the report prints them together without merging them.
The other trap is the county. The finalized federal record files many events by county zone rather than by point. A county-level record has no location to measure from: it does not sit at the county seat, or at the centroid, or anywhere; it sits in the county. The report lists such a record with the county named and no distance, rather than a distance computed from a point the record never stated. A county record given a precise distance elsewhere is carrying a figure the source did not provide.
- A point record
- Filed with coordinates. The report states its distance and bearing from the address and bands it.
- A county record
- Filed to a county zone. The report names the county and states no distance, because there is none to state.
- A radar-derived size
- Computed for a grid cell. The report states the cell's distance, marks the figure as detected and not measured, and draws the swath from it.
What a city radius means on the free pages
The hail-history page for a city, the storm-day pages and the date-of-loss finder all count reports within 10 miles of a fixed centre: the Census centre of the city, or the centre of the address the finder was given. The radius is stated on every figure, and it is the same on every page, so a count on one page can be compared with a count on another.
A radius around a city centre is a different instrument from a distance from a roof, and the free pages say so. It answers whether a citable record exists near a place, from which kinds of evidence and how far back. It does not answer what reached any property, because a circle 10 miles across a city contains every roof in it and says the same thing about each. Two neighbouring cities share the reports that fall between them, and their counts overlap rather than adding up. The pages count days rather than reports for the same reason: four sources describing one afternoon are one afternoon of hail.
A day on those pages counts as severe when its largest report reached 1.00″, the National Weather Service criterion. A city page that shows a severe day does not show which roofs the severe hail fell on. That is the step from the region to the address, and it is the step the report exists to take.
Citing a report at a distance
A citation to a distant report holds up when it claims exactly what the record supports and nothing past it. The form that survives a challenge states four things and leaves out a fifth.
- The date, and the time where the source filed one, as the source filed them.
- The size, with whether it was measured on the ground or detected by radar, in the source's own units.
- The distance and the bearing from the address, or the county where the record has no point.
- The source the record came from, so the reader can find the same line in the federal record.
What it leaves out is causation. A report cited at a distance says hail of a stated size was measured that far away on that day; it does not say the hail damaged the roof, and a citation that says so is carrying a claim the record cannot. The strongest file is rarely the one with the closest single report. It is the one where several independent sources carried the same day, a measured stone sits inside the primary band, a radar-derived size covers the roof, and every figure is printed with its provenance. The free pages show how many sources carried a day; the report shows which, and at what distance from the address.
Questions this guide answers
- How far away can hail be reported and still count
- The report bands every record by its distance from the address: primary within the inner radius, contributing within the outer one, and on record beyond it. A primary report says hail of that size was measured near the property on the date; a contributing report says the storm was in the area that day.
- Does a hail report at a distance prove hail reached the roof
- No. A report establishes that hail of a stated size was measured at a stated place and time. The inference from that point to a roof is the reader's, and what the hail did to the roof is the inspection's to say.
- Why does a county record carry no distance
- Because it was filed to a county zone rather than a point. It does not sit at the county seat or the centroid; it sits in the county. The report names the county and states no distance, since there is none to state.
- What does a city radius on the free pages mean
- The city pages and the date-of-loss finder count reports within a fixed radius of a centre, so a count on one page can be compared with another. A radius around a city says the same thing about every roof in it; the report measures from the address.
From the record
23 Aug 2026
The most recent day with its own page
- Hail reports on the day
- 40
- Largest measured on the ground
- 1.75″
- Independent sources
- 2
- States filed under
- 14
On 23 August 2026 the record holds 40 hail reports filed under 14 states, carried by 2 independent sources. Every one of them is a point, and none of them is a roof.
Measured Detected, not measured
The page these figures come fromRelated
The terms this page uses and the guides that go further. Each is shown against its own example from the record.
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Term
Hail swath
The area a storm is estimated to have dropped hail of a given size over, drawn on a map from radar analysis or traced between ground reports.
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Term
Warning polygon
The area a forecaster draws when issuing a severe thunderstorm or tornado warning, inside which the warning applies and outside which it does not.
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Term
Independent source
A record-keeping route by which a storm reached the archive, counted once however many rows it produced, so that agreement between routes can be measured.
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Term
Storm day
A calendar date on which hail, wind or tornado reports were filed, counted as one day however many reports it carries.
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Guide
Measured and detected: radar hail sizes against spotter reports
The record keeps a stone measured on the ground apart from a size computed from radar, because a court will ask which is which. This guide names the kinds of evidence as the report names them, states what a radar-derived size can and cannot say, explains why a measurement is drawn as a filled mark and a detection as a hollow one, and shows how to read the two on the same day.
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Guide
Which storm caused it: attributing damage across several storm days
Most roofs in the hail belt have been under more than one storm, and a claim is rarely argued against a blank record. It is argued against the other days: the one before the policy began, the one the last carrier paid, the one nobody noticed. This guide sets out what the law asks when storms compete for the same damage, how an appraisal panel reads the record, and why the calendar has to be on the table before the argument starts.
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Guide
How to read a hail report: what each figure means
A hail report is a list of records with figures attached, and every figure on it came from somewhere in particular. This guide walks the document in the order a reader takes it: the date and the window searched, a measured size beside a detected one, the distance and bearing from the address, the count of independent sources, and the line at the end that says what the report does not claim.
Sources
The primary references. Each opens on the agency's own site.
The finder lists every day with hail on record within 10 miles of an address in the last 2 years, ranked by how many independent sources carried it, so the day a file names is a day the record holds.
The guide explains the record. The report is what cites it.
Everything above is explanation: what the record is, how it is read, and what a figure in it can establish. None of it says what reached one roof.
Run the address and the archive is searched at the property: the storm, the date, the measured size, the distance and bearing from the roof, and the federal record each figure came from, in a document that states its own method. About a minute.
How this page is made
- The text
- Written by the editors and last revised 23 August 2026. It explains the record and how the report reads it; it contains no figure of its own.
- The example
- Drawn from the archive when the page was compiled, 24 August 2026, and rebuilt daily as the record deepens. Every figure in the panel marked From the record is computed, not written, and links to the page it came from.
- Measured and detected
- A report from a person or an instrument is measured. A radar-derived size is detected, not measured, and is marked as such, here and in every document we issue. The two are never added together.
- What this is not
- An explanation of the record and of how the report reads it. It is not a report on any property, and it states no opinion about one. The coverage page states what the record holds, by kind and by year.
About this record
Everything here is reproduced from public federal and volunteer weather records, as the agencies and observer networks that publish them released it. Titan Weather compiles the record; it does not observe the weather, and it is not affiliated with any source it cites.
No archive holds everything. Storms cross places where nobody is standing, instruments and spotters cover some areas better than others, sources revise their records, and recent reports can take weeks to arrive and settle. Where this page shows nothing, nothing was found in the sources searched, within the period and area it states. That is not a finding that no weather occurred.
These pages describe the public record near a place or on a date. They do not establish what reached any particular property, and nothing here is insurance, legal or engineering advice.