Hail size 1"
2 S Harvester St. Charles County
“Report from mPING: Quarter (1.00 in.). (LSX)”
— NOAA / SPC storm report
Hail in Saint Charles Apr 17, 2026
Both radar surfaces caught this storm: NEXRAD logged 2 hail signatures up to 1.75", and the radar-estimated size reached 0.75" aloft.
Largest hailstone
1.75"
≈ golf ball · the largest NEXRAD radar signature Homes in the hail footprint
594
Ground reports
12
12 hailThe 2nd most severe storm Saint Charles has seen in the last 12 months
Storm severity score
Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.
5.5 /10
- Hail size
- 44 /100
- Homes exposed
- 55 /100
- Ground truth
- 100 /100
Largest hailstone — the top predictor of roof damage.
How many homes sit inside the storm's footprint.
Independent storm reports filed with the NWS.
How Saint Charles 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.
NEXRAD radar signatures
Where NEXRAD flagged hail as the storm passed — point signatures from the radar, which indicate hail overhead rather than confirm what landed.
Max size
1.75"
Detections
2
Radar-estimated hail size
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.
Max size
0.75"
Where Apr 17, 2026 sits in Saint Charles's hail record
This was Saint Charles's 2nd recorded hail day, arriving 33 days after the Mar 15, 2026 storm. By severity it ranks 2nd of the 9 storms we have logged here. Radar put the day's largest stone over Saint Charles at 1.75" — the largest NEXRAD radar signature.
The Apr 17, 2026 convective day was bigger than Saint Charles: the same system put hail over 1,016 other tracked cities, 169 of them in Missouri. Nearest: Ballwin (14 miles south, up to 2"); Chesterfield (18 miles southwest, up to 2"); O Fallon (18 miles northwest, up to 1.5").
These maps are stills from Saint Charles's Apr 17, 2026 storm. In the Overview app the same surfaces are live — radar updating in real time, radar-estimated hail size as it forms, and NWS spotter reports pinned where they're filed — with a radar replay you can scrub back over any past day.
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.
Hail reports
12 reports Hail size 1"
Harvester St. Charles County
“Report from mPING: Quarter (1.00 in.). (LSX)”
— NOAA / SPC storm report
Hail size 1"
2 SSW Harvester St. Charles County
“(LSX)”
— NOAA / SPC storm report
Hail size 1"
1 NE Harvester St. Charles County
“Report from mPING: Quarter (1.00 in.). (LSX)”
— NOAA / SPC storm report
Hail size 1"
2 SE Harvester St. Charles County
“Report from social media... largest hail stone around 1 inch. (LSX)”
— NOAA / SPC storm report
Hail size 1"
2 SW Saint Charles St. Charles County
“Report from mPING: Quarter (1.00 in.). (LSX)”
— NOAA / SPC storm report
Hail size 1"
2 ENE Weldon Spring St. Charles County
“(LSX)”
— NOAA / SPC storm report
Hail size 1"
3 WNW Chesterfield St. Louis County
“(LSX)”
— NOAA / SPC storm report
Hail size 1"
3 NNE Saint Charles St. Charles County
“(LSX)”
— NOAA / SPC storm report
Hail size 1"
3 NE Saint Charles St. Charles County
“Report from mPING: Quarter (1.00 in.). (LSX)”
— NOAA / SPC storm report
Hail size 1"
Cottleville St. Charles County
“(LSX)”
— NOAA / SPC storm report
Hail size 1"
2 W Harvester St. Charles County
“Report from mPING: Quarter (1.00 in.). (LSX)”
— NOAA / SPC storm report
Storm forensics
Read from the arrival times and locations of the NOAA ground reports,
not a radar-measured storm track.
How the storm moved
The storm tracked northeast at roughly 20 mph, based on the timing of ground reports.
Hail was reported over 40 minutes, from to .
Reports came from Harvester, Weldon Spring, Chesterfield, and Cottleville — beyond Saint Charles itself.
What 1.75" hail means for Saint Charles roofs
At an inch and a half, hail cracks shingles, strips granules down to the mat, and dents gutters, vents, and siding. A footprint like this typically produces a wave of insurance claims — and the contractor who reaches the homeowner first usually gets the inspection.
What this storm is worth to a roofer
$7.1M
Potential roof exposure — 594 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
Illustrative jobs
3 jobs
Illustrative work
~$45K
Claims from this storm can typically be filed until around April 2028 — the window to reach these homeowners while it's still open. Deadlines vary by policy and state.
Track hail over Saint Charles on the live map
Radar updates in real time, spotter reports appear on the map as they're filed, and the full Saint Charles storm history — this Apr 17, 2026 storm included — sits underneath. When you're ready, draw this storm's footprint and pull highly accurate homeowner contact information for every address inside it.
Highly accurate contact information starting at $0.23 per address — every contact included. Digital leads cost $15–$40. Start with a 7-day free trial — no credit card required. See pricing
Saint Charles hail history
← All hail in Saint Charles 9 recorded storm days in Saint Charles, MO
Other storms in Saint Charles
Jul 10, 2026
1" Signatures 1" Estimated 0.5"
1
ground report 
Jul 4, 2026
1" Signatures 1" Estimated 0.5"
No ground reports filed 
Jun 25, 2026
0.75" Estimated 0.75"
No ground reports filed 
Jun 11, 2026
0.5" Estimated 0.5"
No ground reports filed 
May 31, 2026
1" Signatures 1" Estimated 0.5"
No ground reports filed 
May 3, 2026
2.5" Signatures 2.5" Estimated 1.5"
No ground reports filed 
Apr 27, 2026
2.5" Signatures 2.5" Estimated 1.5"
14
ground reports 
Mar 15, 2026
0.75" Signatures 0.75"
No ground reports filed
A storm day here is a convective day — it runs from noon to noon
UTC, so late-night hail is grouped with the afternoon storm that
spawned it rather than split across two calendar dates. Ground
reports are public-domain observations from the NOAA Storm
Prediction Center. Radar surfaces are detections and estimates,
not confirmed damage. Last updated Aug 3, 2026.