Hail map for Alton, IL — May 4, 2026
NOAA radar detected hail up to 1.00″ — quarter size — within 5 miles of Alton on May 4, 2026.
- 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
- 0.75″
- 8.0 mi away · Amateur Radio
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.
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What people on the ground measured in Alton, IL on May 4, 2026
4 reports filed with the National Weather Service — 2 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.
- 0.75″ penny size Amateur Radio2 NNE Bethalto, IL · 8.0 mi away6:11 PM CDTMadison County
Lasted about 5 minutes.
- 0.75″ penny size PublicDorsey, IL · 11.3 mi away6:16 PM CDTMadison County
Twitter report.
- 0.70″ penny size Trained Spotter1 SSE Wood River, IL · 6.3 mi away12:37 PM CDTMadison County
- 0.70″ penny size Trained Spotter2 W Hazelwood, MO · 13.5 mi away11:50 AM CDTSt. Louis County
Spotter estimated dime size hail fell near McDonnell Blvd and I-270.
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 May 4, 2026
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.