Hail map for Alton, IL — August 12, 2025
NOAA radar detected hail up to 1.00″ — quarter size — within 5 miles of Alton on August 12, 2025.
- Max hail size
- 1.00″
- quarter
- Impact rating
- 3/10
- from stone size
- Size bands over the city
- 1
- distinct radar bands
- Measured on the ground
- 1.00″
- 4.1 mi away · Trained Spotter
Sizes come from NOAA MRMS radar (MESH), which runs about ±0.25″ against ground truth. It is canvass-targeting quality, not claim evidence.
Work Alton on the live hail map
- The whole state around Alton, with this swath already on it
- Three years of hail swaths, filterable by stone size
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Did hail hit your address?
This page covers Alton as a whole. Check your own address to see every storm on record for your roof — the date and the stone size for each one — and we'll email you the full report to keep.
Check my addressFree, and no account needed to look it up. If hail did hit, you can ask for a free inspection from a vetted local roofer.
Other towns hit on August 12, 2025
What people on the ground measured in Alton, IL on August 12, 2025
One report filed with the National Weather Service — 1 from trained spotters or officials. These are measured stones, not radar estimates, so they are the closest thing to proof that hail actually reached the ground.
- 1.00″ quarter size Trained Spotter2 NW Wood River, IL · 4.1 mi away2:40 PM CDTMadison County
0.5-1 inch hail reported by trained spotter on St. Louis Avenue in East Alton.
Reports come from the National Weather Service Local Storm Report feed, ingested every 15 minutes. A report records where the observer was, not the full extent of the swath — treat it as evidence about the storm, not about any one roof.
Alton hail on August 12, 2025
NOAA radar estimated stones up to 1.00 inches — quarter size — within about 5 miles of Alton that day, across 1 distinct size band. Sizes vary street to street inside a single swath.