Data current as of 2026-10-16 · Sourced from NOAA Storm Events
Over the past five years, the National Oceanic and Atmospheric Administration has recorded 277 hail storms within 25 miles of O'Fallon, MO. Of those, 265 produced hail at least quarter-size — the threshold most insurance carriers consider potentially damaging to asphalt shingles. The largest reported hail in this window was baseball-sized or larger, which can fracture shingle mat and dent metal flashing on contact. 2026 was the most active year on record locally, with 122 documented hail events.
Check Hail History for a Specific Address in O'Fallon| Severity | Count | What it means for roofs |
|---|---|---|
| Catastrophic | 2 events | Baseball+ size, structural roof damage likely |
| Destructive | 25 events | Egg-size, expect mat fractures and gutter damage |
| Severe | 74 events | Ping pong-size, granule loss and bruising common |
| Significant | 164 events | Quarter-size, the standard insurance damage threshold |
| Moderate | 11 events | Marble-size, possible cosmetic damage |
| Minor | 1 event | Pea-size, unlikely to damage modern shingles |
| Year | Reported Hail Events Within 25 mi |
|---|---|
| 2026 | 122 events |
| 2025 | 107 events |
| 2024 | 17 events |
| 2023 | 28 events |
| 2022 | 1 event |
| 2021 | 2 events |
2026 was the busiest hail year on record locally for O'Fallon, with 122 documented events inside the 25-mile radius. Storm activity in O'Fallon typically peaks in spring and early summer, when the jet stream pushes Gulf moisture into the area and supercell thunderstorms become more frequent.
| Date | Location | Severity | Size | NOAA Comments |
|---|---|---|---|---|
| 2026-09-17 | 1 SW Saint Paul, MO | Significant | 1.00" | — |
| 2026-06-25 | Saint Peters, MO | Moderate | 0.75" | — |
| 2026-06-25 | ST PETERS, MO | Moderate | 0.75" | — |
| 2026-05-04 | Troy, MO | Severe | 1.75" | — |
| 2026-05-04 | Saint Ann, MO | Moderate | 0.50" | Half-inch hail estimate near Ashby and St. Charles Rock Road. |
| 2026-05-04 | Elsah, IL | Minor | 0.25" | — |
| 2026-05-04 | 2 W Hazelwood, MO | Moderate | 0.70" | Spotter estimated dime size hail fell near McDonnell Blvd and I-270. |
| 2026-05-04 | Overland, MO | Moderate | 0.70" | Pea to dime size hail falling in Overland. Multiple reports have originated from this area. |
| 2026-05-04 | 2 SW Cave, MO | Significant | 1.00" | Report from mPING: Quarter (1.00 in.). |
| 2026-05-03 | TROY, MO | Severe | 1.75" | — |
| 2026-05-03 | SOUTH TROY, MO | Significant | 1.00" | — |
| 2026-05-03 | HINES, MO | Severe | 1.75" | — |
| 2026-04-27 | PACIFIC, MO | Significant | 1.00" | — |
| 2026-04-27 | GRAY SUMMIT, MO | Significant | 1.25" | — |
| 2026-04-27 | 1 SW Pacific, MO | Significant | 1.00" | Report from mPING: Quarter (1.00 in.). |
| 2026-04-27 | 2 E Gray Summit, MO | Significant | 1.25" | Report from mPING: Half Dollar (1.25 in.). |
| 2026-04-27 | Warrenton, MO | Significant | 1.00" | — |
| 2026-04-27 | WARRENTON, MO | Significant | 1.00" | — |
| 2026-04-27 | Warrenton, MO | Significant | 1.00" | time estimated. |
| 2026-04-27 | WARRENTON, MO | Significant | 1.00" | — |
NOAA has recorded 129 high-wind events within 25 miles of O'Fallon, MO in the past five years. Of those, 129 reached severe-thunderstorm thresholds (58+ mph). The highest measured gust was 100 mph.
| Severity | Count |
|---|---|
| Destructive | 1 event |
| Severe | 84 events |
| Significant | 44 events |
| Date | Location | Gust (mph) | Severity | NOAA Comments |
|---|---|---|---|---|
| 2026-07-11 | 3 ESE Kampville, MO | 63 | Significant | Corrects previous tstm wnd dmg report from 3 ESE Kampville. Corrects previous non-tstm wnd gst report from 3 ESE Kampville. backyard weather station in New Town measured 63 mph. |
| 2026-06-25 | KAMPVILLE, MO | 60 | Significant | A severe thunderstorm produced strong winds which brought down power lines and caused damage to trees. |
| 2026-06-25 | FERGUSON, MO | 58 | Significant | A thunderstorm produced strong winds which snapped a large tree. The tree fell onto a garage and damaged it. |
| 2026-06-11 | FENTON, MO | 58 | Significant | Thunderstorm winds snapped a 1-2 foot diameter tree branch in Sunset Hills. |
| 2026-06-01 | OVERLAND, MO | 58 | Significant | Thunderstorm winds downed a tree onto a home on Maddox and Fowler in Overland. |
| 2026-05-18 | WARRENTON O SLLVN AR, MO | 58 | Significant | Thunderstorm winds downed a large tree. That large tree blocked Highway 47 at Big Creek north of Warrenton. |
| 2026-04-28 | Saint Ann, MO | 60 | Significant | power outage as the wind gust moved in. |
| 2026-04-27 | Gray Summit, MO | 60 | Significant | Estimated wind coupled with golf ball-sized hail. |
| 2026-04-27 | ELLISVILLE, MO | 70 | Severe | Thunderstorm winds caused a swath of tree damage extending from Wildwood northeastward through Spanish Lake. The same storm produced damage in Franklin County, so it's likely there was damage southwest of Ellisville as well. Large trees were downed, with one landing on a home near Clarkson Valley and others falling onto cars in Saint Ann. Thunderstorm winds also removed shingles from a home near Saint John and collapsed 4 buildings in Florissant. |
| 2026-04-27 | ARGENTVILLE, MO | 58 | Significant | Thunderstorm winds downed power lines on Ethlyn Road. |
| 2026-04-27 | TOWER GROVE, MO | 58 | Significant | Thunderstorm winds downed one power line on McCausland and one small tree at IKEA. |
| 2026-04-27 | FERNRIDGE, MO | 60 | Significant | Thunderstorm winds uprooted multiple trees in Creve Coeur. |
| 2026-04-17 | SOUTH TROY, MO | 69 | Severe | Thunderstorm winds caused damage from near the Woodland Airstrip northeast into Winfield. Near the beginning, winds peeled back the roof of an old farm outbuilding and caused a small farm outbuilding to collapse upon itself. Winds blew down tree branches, power lines, and power poles along its path. Between Moscow Mills and Troy, a billboard was blown over onto a mobile home which sustained damage. |
| 2026-04-17 | CAPPELN, MO | 75 | Severe | Thunderstorm winds caused damage to power poles across the far western portion of the county, extending from New Melle north into Wentzville and Flint Hill. Along its path, there were multiple reports of snapped trees/branches, snapped power poles, downed lines, one downed transformer, and one home with shingles missing from its roof near New Melle. This thunderstorm went on to produce additional wind damage in Lincoln County. |
| 2026-04-17 | HARVESTER, MO | 58 | Significant | Thunderstorm winds knocked a tree onto a powerline. |
| 2026-04-17 | MOSCOW MILLS, MO | 58 | Significant | Thunderstorm winds snapped two 6 inch diameter limbs from trees just south of Troy. |
| 2026-04-17 | ETHLYN, MO | 81 | Severe | Thunderstorm winds snapped power poles and numerous tree limbs from just north of Flint Hill northeast to Winfield. Near Old Monroe a farm outbuilding was collapsed, the siding peeled from a home, and the roof removed from a mobile home. |
| 2026-04-15 | BALLWIN, MO | 58 | Significant | Thunderstorm winds caused a large tree limb to fall onto a house. |
| 2026-03-15 | TROY, MO | 58 | Significant | Thunderstorm winds downed a tree on East Cherry Street. Live powerlines were also downed on the same street. |
| 2026-03-15 | DES PERES, MO | 64 | Severe | Thunderstorm winds blew open a strong steel door in Des Peres before splitting a Bradford Pear tree into 2 near Webster Groves. Winds then blew down tree limbs up to 8 inches in diameter along Green Park Industrial Drive 1 mile southeast of Lakeshire. |
The most recent quarter-size-or-larger hail storm recorded by NOAA within 25 miles of O'Fallon was on September 17, 2026. HailCheck refreshes from the NOAA Storm Events database daily, so newer events appear here as they are reported.
O'Fallon averages roughly 55 reported hail events per year within a 25-mile radius. Significant storms (quarter-size or larger) account for 265 of the 277 events recorded over the last five years.
The largest documented hail near O'Fallon in the last five years was baseball-sized or larger. Most O'Fallon-area hail falls in the marble-to-quarter range, with destructive storms (egg-size or larger) appearing roughly once every few years.
Most homeowners insurance policies in MO cover hail damage to roofs, siding, and gutters under the dwelling and other-structures coverage. Coverage typically requires the damage to be tied to a verifiable storm date — which is where the NOAA hail history above (and a HAAG-style test square validation) becomes important for the claim file.
Use the HailCheck address search to enter any street address in or near O'Fallon. HailCheck returns every NOAA hail event within a configurable radius, along with severity bands, dates, and storm narratives for Pro members.
If your property in or near O'Fallon took on hail during one of the storms above, the standard process for documenting damage is a 10×10 foot test square inspection. A HAAG-trained reviewer counts impact indicators — granule displacement, mat fractures, and bruising — within the marked square and produces a PASS or FAIL document for the claim file.
HailCheck offers a $99 photo-based HAAG-style test square validation. You submit photos from the field, our reviewer evaluates the impact indicators and cross-references the NOAA storm dates listed above, and a written PASS/FAIL determination is returned within one business day. We do not send anyone to the roof — the validation is built around the photos you submit.
Learn About $99 HAAG-Style ValidationO'Fallon sits inside the central United States hail belt, where warm Gulf moisture collides with cold continental air to produce supercell thunderstorms capable of dropping the hail documented above. Properties in this zone typically see at least one significant hail event every two to four years.