What Hit My House

Did hail hit this address in the last 24 hours?

Answered on a grid about 1 km across. The rest of this site answers from a 7-mile tile, which is the honest limit of a 1992 archive. This layer is roughly 100 times smaller in area, and the newest reading is usually a couple of minutes old.

Free, no signup, no account. Try Dallas · Denver · Fort Worth. Coordinates work too, as 32.78, -96.80.

Why 1 km instead of 7 miles

The complaint every contractor in this trade has about swath maps is a distance complaint, and they say it in miles: "a lot of reps waste a day knocking 'hit' areas where the real path missed by half a mile". A 7-mile tile cannot answer a half-mile question. It was never built to.

LayerAnswersGridCovers
Radar historyHas hail ever been detected near here, and how often 0.1°, ~7 miles1992 to now
This pageWhat the radar estimated over these cells, and when 0.01°, ~1 kmLast 24 hours, and the current scan
Reported hailWhat a person said they saw, in their words A pointLast 7 days

They are three different kinds of fact and they are worth reading together. Radar saw something. A person measured something. Those agreeing is worth more than either alone.

What this is, and what it is not

MESH is an estimate, not an observation. Maximum Estimated Size of Hail, derived from radar reflectivity aloft and the height of the freezing level. Nobody stood there with a ruler.

A finer grid buys precision about WHERE, not about WHAT. It tells you the estimate applies to this square kilometre rather than to a 7-mile box. It tells you nothing more about what is on the roof than the coarse version did.

Zero is an absence of estimate, not proof nothing fell. The radar did not estimate hail over these cells. That is a different sentence from "no hail fell here".

NOAA's own published evaluation of this product, against 21,184 ground-truth reports, states that exact MESH values "should not be used as a direct proxy for the actual hail size that fell", and that MESH is useful for hail detection but not for size discrimination (Ortega 2018, EJSSM 13(1)). It is deliberately calibrated so that roughly three quarters of real stones are smaller than the number reported, and it has no demonstrated skill at the 2-inch threshold. Nothing on this page keys to 2 inches, and the size is never the headline. A roof still has to be inspected by a person.

Source

NOAA MRMS (Multi-Radar Multi-Sensor), products MESH and MESH_Max_1440min. US Government work, public domain, no API key and no account. This page runs on our own free keyless JSON endpoint, so you can call it from your own tools and check the numbers rather than take ours. Not affiliated with or endorsed by NOAA or the National Weather Service.

Where hail was reported this week · For contractors · Full hail history for one address · Reported hail, last 48 hours

What Hit My House · Fredericksburg, Virginia · hello@whathitmyhouse.com
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