Tornadoes are among the most destructive weather phenomena on Earth, capable of reducing well-built homes to rubble in seconds. While tornadoes can strike anywhere in the United States, certain counties face dramatically higher exposure due to their location within Tornado Alley and the Dixie Alley.
Using FEMA National Risk Index tornado risk scores, we identified the 25 most tornado-prone counties in America.
The 25 Most Tornado-Prone Counties in America
Harris County, Texas has the highest tornado risk score at 100. These counties face the greatest tornado exposure:
| Rank | County | State | Tornado Risk | Composite Risk | Flood Risk |
|---|---|---|---|---|---|
| 1 | Harris County, Texas | TX | 100 | 99.9364 | 99.9682 |
| 2 | Cook County, Illinois | IL | 99.9682 | 99.9682 | 99.9364 |
| 3 | Collin County, Texas | TX | 99.9364 | 98.855 | 96.7875 |
| 4 | Bexar County, Texas | TX | 99.9046 | 99.4275 | 99.6501 |
| 5 | Tarrant County, Texas | TX | 99.8728 | 99.1412 | 99.1412 |
| 6 | Dallas County, Texas | TX | 99.841 | 99.6501 | 99.5547 |
| 7 | Denton County, Texas | TX | 99.8092 | 96.9148 | 95.7061 |
| 8 | Shelby County, Tennessee | TN | 99.7774 | 99.3639 | 98.6641 |
| 9 | Jefferson County, Kentucky | KY | 99.7455 | 98.2824 | 99.1094 |
| 10 | Oakland County, Michigan | MI | 99.7137 | 97.5191 | 97.4873 |
| 11 | Travis County, Texas | TX | 99.6819 | 97.7417 | 98.3461 |
| 12 | Hillsborough County, Florida | FL | 99.6501 | 98.8232 | 97.7735 |
| 13 | Hennepin County, Minnesota | MN | 99.6183 | 98.3142 | 98.028 |
| 14 | East Baton Rouge Parish, Louisiana | LA | 99.5865 | 97.9644 | 97.3282 |
| 15 | Jefferson County, Alabama | AL | 99.5547 | 97.6145 | 98.0916 |
| 16 | Oklahoma County, Oklahoma | OK | 99.5229 | 97.9326 | 97.6463 |
| 17 | Wayne County, Michigan | MI | 99.4911 | 98.9504 | 99.3957 |
| 18 | Jackson County, Missouri | MO | 99.4593 | 96.5013 | 96.5013 |
| 19 | Montgomery County, Texas | TX | 99.4275 | 95.7379 | 95.5789 |
| 20 | Douglas County, Nebraska | NE | 99.3957 | 95.8651 | 95.07 |
| 21 | Hamilton County, Ohio | OH | 99.3639 | 96.3422 | 96.9148 |
| 22 | DuPage County, Illinois | IL | 99.3321 | 97.6463 | 97.9962 |
| 23 | Macomb County, Michigan | MI | 99.3003 | 96.6603 | 97.4555 |
| 24 | Sedgwick County, Kansas | KS | 99.2684 | 96.5967 | 96.0878 |
| 25 | Will County, Illinois | IL | 99.2366 | 97.2646 | 97.869 |
Methodology
Tornado risk scores come from the FEMA National Risk Index (2020), measuring expected annual loss from tornadoes at the county level. Scores are percentile ranks on a 0-100 scale. Counties are ranked by tornado risk score in descending order.
Data source: FEMA National Risk Index (NRI). Risk scores use percentile-rank methodology on a 0-100 scale. All figures are relative rankings and do not represent absolute predictions of natural disaster occurrence.