What Is a Hail Map?

Radar can estimate hail size and track a storm’s path, and observations from spotters, weather stations, and the public correct and extend those estimates. Mapping services shade areas by estimated stone size and attach the storm date, so a street can be checked after the fact. The maps are estimates, not measurements of any single roof.

Canvassing and appointment-setting teams read a hail map to pick where to send people, which streets to call first, and which storms are worth the effort. Because a dated map shows what likely struck an address, it can back up the cause and timing of a claim when paired with an inspection. Managers compare the map with the age of local roofs, since older roofs often show damage at smaller sizes.

The most common error is treating the map as proof of damage. A shaded area means hail probably fell; whether a specific roof was damaged depends on its age, material, wind direction, and condition, and only an inspection settles it. Radar-based sizes can run over or under what hit the ground, and boundaries blur at street level. Telling a homeowner the map proves a claim promises more than it can deliver.