Hail in Alton · Sep 5, 2026
The estimated-size surface reached 0.5" aloft; NEXRAD logged no point detections over Alton that day. Open it on the live map to see the swath over the streets.
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Convective day · Sep 5, 2026 · noon–noon UTC
Severity
The 5th most severe storm Alton has seen in the last 12 months
Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.
- Peak hail signal
- 13 /100
- Homes exposed
- 55 /100
- Ground truth
- 0 /100
Largest radar-indicated size — a signal of damage potential, not confirmation.
How many homes sit inside the storm's footprint.
Independent storm reports filed with the NWS.
Evidence / storm surfaces
How Alton saw the hail — from two instruments
The maps here read the same storm from two angles — point detections from NEXRAD, and modeled hail size aloft. Where the two disagree is informative: it marks where estimated size outran the signatures, or trailed them.
Estimated size field The modeled maximum hail size across the swath, derived from radar aloft — the largest stone the storm could have supported, which is not necessarily what reached the ground.
Only the radar-estimated size surface resolved for Sep 5, 2026 — this storm produced no NEXRAD point detections over Alton, so there is one map to show, not two.
The storm in context
Where Sep 5, 2026 sits in Alton's hail record.
This was Alton's 5th recorded hail day, arriving 124 days after the May 4, 2026 storm. By severity it ranks 5th of the 5 storms we have logged here. Radar put the day's largest stone over Alton at 0.5" — radar-estimated size aloft.
The Sep 5, 2026 convective day was bigger than Alton: the same system put hail over 514 other tracked cities, 10 of them in Illinois. Nearest: Kampsville (42 miles northwest, up to 0.5"); Elsberry (43 miles northwest, up to 0.5"); Eolia (48 miles northwest, up to 0.5").
These maps are stills. In the app this date is one of 5 Alton storm dates on a live map — both surfaces, the reports, and a replay — and the same map is where you draw the swath. This page rebuilds nightly.
Ground reports
What people on the ground reported
These are storm reports filed with the National Weather Service and released through the NOAA Storm Prediction Center — public-domain observations from spotters, the public, and NWS surveys. We quote each one exactly as filed.
Nobody on the ground filed a report over Alton for this date, which says more about who was watching than about the storm: spotter reports only exist where there is an observer. The radar surfaces above carry the evidence for this one.
Below the severe threshold
What 0.5" hail means for Alton roofs.
Radar signals under three-quarters of an inch stay below the National Weather Service severe threshold and generally indicate lower roof risk. Older or already-worn materials can still show effects, but radar alone cannot determine whether a specific roof was damaged.
Radar reading · not confirmed damage
Roofing exposure
What this storm is worth to a roofer.
Potential roof exposure
$6.4M
Potential roof exposure — 530 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
- Illustrative jobs
- 3 jobs
- Illustrative work
- ~$45K
Close just 0.5% of the 530 homes in this footprint at the average $15,000 roof job. Illustrative math, not a projection — your results depend on your outreach and how the market responds.
Claim window
September 2028
Claims from this storm can typically be filed until around September 2028 — the window to reach these homeowners while it's still open. Deadlines vary by policy and state.
Names and phones for every home in the footprint: at most $111 on top of the $150 plan.
Estimated-size surface May 4, 2026
2.25"
Estimated-size surface May 3, 2026
1.75"
Estimated-size surface Apr 27, 2026
2.75"
Estimated-size surface Mar 15, 2026
1"Take your next area into the field.
See the hail, review your recommendations, and canvass with Overview on iPhone.
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