O'Fallon, MO
Local storm history & FEMA National Risk Index data
O'Fallon is rated Relatively Moderate for overall natural hazard risk — near the middle compared to other US counties — based on FEMA's National Risk Index for St. Charles County, MO. The county's highest-rated hazards are strong wind, hail, and tornado.
Storm events near O'Fallon
NOAA-recorded tornado, hail, and flood events within 25 miles of O'Fallon's center, 2016–2026 — the only hazards NOAA reports with exact coordinates, so these counts are specific to O'Fallon itself, not the whole county.
County-wide hazard risk
Every other hazard FEMA and NOAA track — including drought — is only scored at the county level. These are St. Charles County's FEMA National Risk Index scores, covering O'Fallon along with the rest of the county, not a O'Fallon-specific figure.
| Hazard | NRI score | Rating |
|---|---|---|
| Wildfire | 58.8 | Very Low |
| Inland Flooding | 94.2 | Relatively High |
| Coastal Flooding | — | Not Applicable |
| Earthquake | 94.6 | Relatively Moderate |
| Heat Wave | 95.6 | Relatively Moderate |
| Tornado | 96.4 | Relatively High |
| Avalanche | — | Not Applicable |
| Cold Wave | 92.7 | Relatively High |
| Drought | 32.3 | Relatively Low |
| Hail | 97.6 | Relatively High |
| Hurricane | 22.8 | Very Low |
| Ice Storm | 71.6 | Relatively Moderate |
| Landslide | 92.8 | Relatively Moderate |
| Lightning | 89.7 | Relatively High |
| Strong Wind | 98.1 | Very High |
| Tsunami | — | Not Applicable |
| Volcanic Activity | — | Not Applicable |
| Winter Weather | 89 | Relatively High |
Source: FEMA National Risk Index v1.20.0, December 2025. See the methodology page for definitions, or the full St. Charles County risk profile for disaster declarations, social vulnerability, and climate projection data.
Other cities in St. Charles County:
More on St. Charles County:
Frequently asked questions
What natural hazards is O'Fallon, MO at risk of?
O'Fallon is rated Relatively Moderate for overall natural hazard risk by FEMA's National Risk Index — near the middle compared to other US counties. The highest-rated hazards for St. Charles County, where O'Fallon is located, are strong wind, hail, and tornado.
What is O'Fallon's biggest natural hazard risk?
Strong Wind is the highest-rated hazard for St. Charles County, where O'Fallon is located, scoring 98.1 out of 100 on FEMA's National Risk Index (rated "Very High").
Is O'Fallon a high-risk area for natural disasters?
Somewhat — O'Fallon carries near the middle compared to other US counties for overall natural hazard risk, per FEMA's National Risk Index rating of "Relatively Moderate" for St. Charles County.
Has O'Fallon had tornadoes, hail, or flooding?
NOAA has recorded 31 tornado, 238 hail, 52 inland flooding events within 25 miles of O'Fallon since 2016.