Hail history for O'Fallon, Illinois
NOAA hail reports in and within about 5 km (3 miles) of O'Fallon since 1971, with preliminary reports to November 3, 2026.
Readout · O'Fallon
- Last hail
- Apr 2, 2025
- 1.75 in, golf ball size
- Hail days, last 5 years
- 2
- since Nov 3, 2021 · 6 reports
- Largest ever
- 3.50 in
- teacup · Apr 28, 2012
26 reports on 21 days since 1971 · #76 of 378 Illinois places
Hail map · O'Fallon
- Under 1 in
- 1–1.75 in
- 1.75–2.5 in
- 2.5–4 in
- 4 in +
- No size
For homeowners
Roof damage after hail? Get a free inspection
Hail bruises shingles and cracks seals in ways you can't see from the ground, and most insurers set a claim deadline after the storm. The latest hail report in O'Fallon is from April 2, 2025. A local roofer can check and document it at no cost.
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What the record says about O'Fallon
The latest hail report in and around O'Fallon is from April 2, 2025, 1.75 in (golf ball size). Since November 3, 2021 there have been 2 separate hail days; the biggest stones in that time were 1.75 in on April 2, 2025.
Over the 20 years 2006–2025, O'Fallon logged 16 reports on 11 hail days, about 0.8 reports a year. That is 60% more than the median Illinois town on this site (0.5 a year) and ranks #76 of 378 Illinois cities and towns on this site for all-time reports. O'Fallon accounts for 8% of the 319 reports filed in St. Clair County.
4% of reports with a size were 2 inches (hen egg) or larger, against 4% for the median Illinois town on this site. The largest hail on record here is 3.50 in (teacup) on April 28, 2012 near 0.81 SW Carbon.
Reports were up 67% in 2016–2025 (10) compared with 2006–2015 (6). The busiest year was 2025, with 6 reports on 2 days. Hail here peaks in March (23% of reports); 58% fall between April and June.
Reports a year 2006–2025 average
- O'Fallon 0.8
- St. Clair County 8.5
- Median Illinois town on this site 0.5
Hail days 2006–2025
- O'Fallon 11
- St. Clair County 90
- Median Illinois town on this site 8
Share 2 in or larger of sized reports
- O'Fallon 4%
- St. Clair County 6%
- Median Illinois town on this site 4%
Hail over time
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | 0 | ||||||||||||
| 2025 | 5 | 1 | 6 | ||||||||||
| 2024 | 0 | ||||||||||||
| 2023 | 0 | ||||||||||||
| 2022 | 0 | ||||||||||||
| 2021 | 0 | ||||||||||||
| 2020 | 0 | ||||||||||||
| 2019 | 2 | 1 | 3 | ||||||||||
| 2018 | 1 | 1 | |||||||||||
| 2017 | 0 |
Hail days since Nov 3, 2021
| Date | Reports | Largest | Storm page |
|---|---|---|---|
| Apr 2, 2025 | 1 | 1.75 in | — |
| Mar 14, 2025 | 5 | 1.75 in | — |
Largest hail on record
| Date | Size | Location | County | Time · source |
|---|---|---|---|---|
| Apr 28, 2012 | 3.50 inteacup | 0.81 SW Carbon | St. Clair | 15:05 local · NCEI |
| Apr 2, 2025 | 1.75 ingolf ball | 1.38 N Willard | St. Clair | 15:44 local · NCEI |
| Mar 14, 2025 | 1.75 ingolf ball | 0.88 SW O Fallon | St. Clair | 21:25 local · NCEI |
| Jul 4, 1982 | 1.75 ingolf ball | — | St. Clair | 14:55 local · NCEI |
| May 29, 1974 | 1.75 ingolf ball | — | St. Clair | 10:30 local · NCEI |
Sizes filed before 1996 are often rough estimates (round numbers like 7.00 or 8.00 in) without an exact spot; they are shown as NOAA filed them.
Size of every report
- Under 1 in 5 19%
- 1–2 in 20 77%
- 2 in + 1 4%
Most recent reports
| Date | Size | Location | County | Time · source |
|---|---|---|---|---|
| Apr 2, 2025 | 1.75 ingolf ball | 1.38 N Willard | St. Clair | 15:44 local · NCEI |
| Mar 14, 2025 | 1.00 inquarter | 0.88 SW O Fallon | St. Clair | 21:30 local · NCEI |
| Mar 14, 2025 | 1.00 inquarter | 1.38 N Willard | St. Clair | 21:28 local · NCEI |
| Mar 14, 2025 | 1.75 ingolf ball | 0.88 SW O Fallon | St. Clair | 21:25 local · NCEI |
| Mar 14, 2025 | 1.00 inquarter | 0.69 S Willard | St. Clair | 21:25 local · NCEI |
| Mar 14, 2025 | 1.00 inquarter | 0.88 SW O Fallon | St. Clair | 21:06 local · NCEI |
| Aug 19, 2019 | 1.25 inhalf dollar | O Fallon | St. Clair | 17:20 local · NCEI |
| Apr 30, 2019 | 1.00 inquarter | 4 SE Collinsville | St. Clair | 14:10 local · NCEI |
| Apr 18, 2019 | 1.25 inhalf dollar | 0.78 SSW Black Jack | Madison | 00:37 local · NCEI |
| May 27, 2018 | 1.50 inping pong ball | 2.38 NE O Fallon | St. Clair | 17:20 local · NCEI |
| May 31, 2013 | 1.00 inquarter | 1.3 SSW O Fallon | St. Clair | 20:15 local · NCEI |
| Apr 28, 2012 | 3.50 inteacup | 0.81 SW Carbon | St. Clair | 15:05 local · NCEI |
Hail history near O'Fallon
- Shiloh 5 km · 11
- Scott AFB 8 km · 13
- Fairview Heights 8 km · 10
- Belleville 11 km · 61
- Caseyville 11 km · 10
- Collinsville 12 km · 31
- Mascoutah 14 km · 32
- Troy 14 km · 19
Questions about hail in O'Fallon
How often does it hail in O'Fallon, Illinois?
26 hail reports have been logged in and within about 5 km (3 miles) of O'Fallon since 1971. Over the 20 years 2006–2025 that averages 0.8 reports a year. That ranks #76 of 378 Illinois places by number of reports.
When is hail season in O'Fallon?
Most reports come in March, April, May. March alone accounts for 23% of all reports.
What is the largest hail recorded in O'Fallon?
3.50 in (teacup size) on April 28, 2012 near 0.81 SW Carbon. 4% of reports here were 2 inches or larger.
When did it last hail in O'Fallon?
The most recent report in this data is from April 2, 2025 (1.75 in). Final NOAA data runs to July 31, 2026; preliminary NWS reports run to November 3, 2026.
How many hail storms has O'Fallon had in the last five years?
2 separate days with hail reports since November 3, 2021, adding up to 6 reports. The most recent was April 2, 2025.
Where does this hail data come from?
Hail reports come from the NOAA NCEI Storm Events Database, which the National Weather Service compiles from spotter, public, law enforcement and media reports. Recent days use preliminary NWS Local Storm Reports via the Iowa Environmental Mesonet until NOAA publishes final data. Only reported hail is counted, so areas with fewer people tend to have fewer reports.