National Storm Dispatch

How we source our hail and wind data

This site does two things: it connects homeowners with local roofing contractors who handle storm damage, and it publishes the recent weather readings we hold for each postcode so people can decide whether an inspection is worth booking.

Roof damage from hail and wind is frequently invisible from the ground, so we deliberately publish readings rather than conclusions. Nothing on this site is a substitute for someone getting on the roof and looking at it.

Where each number comes from

Weather readings

Open-Meteo forecast API, which aggregates output from national weather service models. For each postcode we store the highest recent daily precipitation total, precipitation hours, a multi-day precipitation sum, and the strongest daily wind gust for that postcode's coordinates. Precipitation is liquid-equivalent rain/hail total — not hailstone diameter. We do not operate weather stations and we do not measure anything at your property.

Official nearby reports and alerts

United States: NOAA Storm Prediction Center local storm reports (hail size in inches, wind/damage reports) for today and yesterday. Australia: Bureau of Meteorology land-warning RSS for live severe thunderstorm / severe weather / flood-style warnings, matched to postcodes by forecast district (town anchors within ~75 km — never a whole-state blast), plus the Severe Storms Archive event catalogue which can lag real time. Canada: Environment and Climate Change Canada weather alerts and thunderstorm outlooks via GeoMet, matched when a polygon covers the postcode. These sources are named only to describe origin; none of them endorse this site.

Housing density

Published national census sources — the US Census Bureau, the Australian Bureau of Statistics, and Statistics Canada — expressed as dwellings per square mile or square kilometre for the surrounding area.

Typical build year

Published census construction-year data, shown only where the source actually holds it. The Australian census does not collect dwelling construction year, so Australian pages omit the figure entirely rather than estimate it.

Severe readings counter

A running count of how many times a postcode's readings have crossed our severe threshold since we began monitoring it. It starts from zero at that point and is not a historical storm record.

How the sector status is calculated

The status on each postcode panel is a plain threshold we apply ourselves so the page can be read at a glance. It is our own rule of thumb — not an industry standard, not a hazard rating, and not an insurance classification. The exact rules are:

Critical ThreatA nearby official hail report of about 1.00 in (2.5 cm) or more, or a highest recent daily precipitation total of 1.25 in (31.75 mm) or more. The 1.00 in hail figure mirrors the common US NWS severe-thunderstorm hail criterion; precipitation alone is still only a rain/hail total from the weather model.
Moderate ExposureAny nearby official hail report, any recorded precipitation, a peak gust of 40 mph (64 km/h) or more, or an official severe-weather alert that covers the postcode.
Baseline SurveillanceNone of the above.

Thresholds are expressed in inches and miles per hour because that is how we store readings; pages in Australia and Canada convert them to millimetres and kilometres per hour for display.

How current the readings are

Postcodes are refreshed on a rotating queue rather than continuously, so this is not a live feed. Every postcode page shows the timestamp of its own most recent collection, and that timestamp is the only freshness claim we make. If a page has never been collected it says so instead of showing a substitute date.

Because the queue rotates, a very recent or very localised storm may not appear in the readings yet.

What this data cannot tell you

  • Whether your roof is damaged. Storms are patchy, our readings cover a whole postcode, and roof condition depends on the age and type of covering.
  • Hailstone diameter from the precipitation figure alone. Open-Meteo reports liquid-equivalent precipitation, not hail size — we only quote hail size when a nearby official report supplies one.
  • Whether an insurer will accept a claim. We are not involved in claims and have no view on policy terms.
  • That a low reading means the roof is fine. Roofs also fail from age, or from a storm we never recorded.

Independence and affiliation

We are not affiliated with, endorsed by, accredited by, or certified by any weather agency, census authority, standards body, trade association, or insurer. Where we name a data source, we name it only to describe where a number came from. Threshold anchors such as NWS severe criteria are reference points for our own labels — not a claim that NWS, BOM, or ECCC reviewed this site.

Contractors who receive requests are independent businesses. In the field they typically work to the trade practices normal for their discipline — for example HAAG-style roof documentation, ISA TRAQ tree risk assessment, or IICRC S500 water restoration. Those frameworks describe contractor work; they do not define the weather thresholds published here.

We are not a contractor and carry out no field work. Assessment, pricing, and any work performed are matters between the contractor and the homeowner.

Corrections

If a reading, city name, or postcode on this site looks wrong, we want to know. Contact details and the process for data requests are on our terms and privacy page. Corrections to underlying weather or census data have to be raised with the original source, but anything we have mapped incorrectly we can fix.