Which covered Iowa cities have the highest relative tornado risk?
Iowa City use FEMA data for Johnson County, which has the highest relative tornado score in this covered set at 98.4/100. Cities sharing the same FEMA area share the same score.
Tornado Risk by City in Iowa
Compare 6 cities using FEMA's relative tornado scores and annualized frequency for the county-equivalent areas shown.
Highest relative score
98.4/100
Johnson County
Covered cities: Iowa City
Lowest relative score in this set
83.9/100
Scott County
Covered cities: Davenport
These are relative FEMA scores for county-equivalent areas. They are not annual probabilities or property-level findings.
Iowa tornado rankings
Cities sharing a FEMA area are grouped together and receive the same score.
| Rank | FEMA area and cities | Rating | Score | Annualized frequency |
|---|---|---|---|---|
| #1 | Johnson County | Relatively High | 98.4/100 | 0.59 events per year |
| #2 | Polk County | Relatively High | 98.3/100 | 0.58 events per year |
| #3 | Woodbury County | Relatively High | 96.4/100 | 0.76 events per year |
| #4 | Linn County | Relatively High | 95.6/100 | 0.67 events per year |
| #5 | Black Hawk County | Relatively Moderate | 92.0/100 | 0.54 events per year |
| #6 | Scott County | Relatively Moderate | 83.9/100 | 0.42 events per year |
FEMA annualizes recorded qualifying tornado occurrences across the FEMA geography and source period.
Preparing for tornado
Ready.gov Tornadoes ↗For a home or move
- ✓Identify the lowest-floor interior room or nearby rated shelter you can reach quickly.
- ✓Review how garage doors, roof connections, and exterior objects could perform in severe wind with a qualified local professional.
- ✓Confirm that insurance documents cover wind damage and understand the deductible before storm season.
For a household plan
- ✓Enable Wireless Emergency Alerts and keep a battery-powered NOAA Weather Radio available.
- ✓Keep shoes, flashlights, and head protection in or beside the shelter location.
- ✓Practice reaching the shelter with children, pets, and anyone who needs mobility assistance.
Questions about tornado risk in Iowa
Which covered Iowa area has the lowest relative tornado score?
Scott County has the lowest score in this covered set at 83.9/100. This is a relative FEMA comparison, not a declaration that every property there is safe.
Are these tornado figures city-level?
No. The city links provide geographic navigation, while the scores and frequencies cover the FEMA county-equivalent areas shown in the table. Address-level conditions require local maps and property details.
Is the FEMA relative score an annual probability?
No. The relative score compares FEMA areas on a 0–100 scale. Annualized frequency appears separately with hazard-specific units.
Source: FEMA National Risk Index v1.19.0, released March 2023. Hazard data covers FEMA county-equivalent areas.