What Is HailScore?

What does HailScore do?

HailScore answers one question: how much hail has a specific address been exposed to over the past decade? You enter any US street address and instantly receive a HailScore between 0 and 100, calculated from real government radar and ground-truth weather records rather than estimates or guesses.

The score is built on 8.6M+ verified hail records drawn from six independent sources, anchored by 5.9M+ NOAA NEXRAD radar hail signatures. Every lookup returns a score, an interactive map of nearby hail events, a year-by-year history, and the date the data was last refreshed.

Exposure, not damage — why the distinction matters

A high HailScore means significant hail has passed over or near the property according to verified records. It does not assert that the roof is damaged. Only a physical inspection can confirm actual damage.

How is the score calculated?

The HailScore algorithm (version 6, recalibrated May 2026) combines three weighted components and then adjusts for the roof itself:

• Hail size (up to 40 points) — larger hailstones are weighted on an accelerating curve because impact energy rises faster than diameter.
• Frequency (up to 30 points) — how many significant hail events (≥0.75 inches) have occurred near the address, on a logarithmic scale.
• Recency (up to 30 points) — recent hail is weighted more heavily than old hail, on roughly a 10-year half-life.
• Distance decay — events directly over the property count fully; nearby events are discounted by distance, within roughly an 8-mile radius.
• Roof age and material — the score only counts hail that fell within the roof's lifetime, then adjusts for how vulnerable the roofing material is.

The full methodology is published openly for transparency and peer review.

Who uses HailScore?

• Homeowners — to know their hail exposure before damage shows up, and to decide whether an inspection is worth scheduling.
• Roofing contractors — to show homeowners real government data instead of a sales pitch.
• Insurance adjusters and public adjusters — to verify whether hail actually occurred at a claimed address and date against raw NOAA records.
• Attorneys — for date-of-loss verification grounded in primary government sources.
• Real estate professionals — for roof-condition and storm-history context.

Frequently asked questions