How we count hail
Everything on Hail Proof Report comes from public NOAA records. Here is what we use, how we count it, and what it can't tell you.
Two kinds of records
- Radar hail signatures. NOAA's NEXRAD radars estimate where hail was likely in a storm, with an estimated size and probability. We read them from NOAA's Severe Weather Data Inventory (the nx3hail dataset). They cover places with no witnesses, but the sizes are estimates.
- Ground reports. National Weather Service reports of hail people saw, from the NOAA NCEI Storm Events Database. They are real sightings, but they can miss areas where nobody reported, and NOAA publishes and revises them with a delay.
We list them separately so you can tell which is which.
What the free address check does
- Finds your address with the U.S. Census Bureau Geocoder.
- Lists every day with a radar hail signature within 3 miles, over the last 3 years. Radar times are converted to local time before grouping, so one evening storm stays on one date.
- Calls a radar day notable if the estimated size is 0.75 inch or larger, or the severe-hail probability is 50% or more.
- Lists every ground report within 10 miles, over the same period.
What city pages count
City pages use a fixed downtown address. They count ground reports within 5 miles over the last 10 full years, and radar hail days within 3 miles over the last 3 years. The current year's ground reports are left out until NOAA finishes that year. A city page describes the area around downtown, not any one house.
What this data can't tell you
- It does not show that hail fell at a particular house. A radar signature is an estimate for an area.
- No report on a date does not prove no hail fell.
- It does not show whether any property has damage. We report weather only.
- It does not say whether to file an insurance claim, and it is not insurance, legal or contracting advice.
Sources
Check an address free · Hail history by Texas city · Storm reports