Story County, Iowa
Natural disaster risk, federal disaster history and flood insurance facts.
Story County, Iowa has a relatively low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 69% of US counties. It ranks 9th of 99 counties in Iowa. The costliest hazards here are inland flooding, tornadoes and drought. FEMA estimates about $36 million a year in expected losses, or roughly $366 per resident. Since 1969 it has been included in 20 federal disaster or emergency declarations for natural events (19 major disasters). The most recent was in September 2026 (severe storms and flooding). Fewer than 1 in 100 homes here carry federal flood insurance (95 policies). Since 1978, federal flood insurance has paid about $13 million on 286 claims here, including $8.3 million for floods in 2010.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Story County
- Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
- Price a flood policy now. Most new federal policies take 30 days to start.
- Pick a shelter spot: a basement, or an inside room on the lowest floor with no windows.
- Turn on emergency alerts on your phone and keep a weather radio.
- Check local water restrictions.
- Choose drought-tolerant plants.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Inland flooding | 69.1 | $16M | ||
| Tornado | 91.3 | $10M | ||
| Drought | 96.4 | $4M | ||
| Hail | 86.8 | $2M | ||
| Strong wind | 69.9 | $1M | ||
| Cold wave | 35.3 | $692K | ||
| Winter weather | 90.2 | $533K | ||
| Lightning | 56.5 | $380K | ||
| Ice storm | 64.2 | $209K | ||
| Earthquake | 34.8 | $142K | ||
| Heat wave | 13.0 | $37K | ||
| Wildfire | 30.3 | $19K | ||
| Hurricane | 14.4 | $5K | ||
| Landslide | 43.6 | $1K |
Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is very low and community resilience is very high in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included Story County. 2020s bar runs to November 2026.
By type
Most recent
Show all 20
Iowa also had 11 statewide declarations that did not name single counties.
Storm history since 1950
Tornado risk by county ›The National Weather Service has logged 1,084 storm reports in Story County since 1950, with 1 death and 32 injuries and about $132 million in reported damage. The strongest on record here was an F5 tornado on June 13, 1976.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Jun 13, 1976 | F5 | – | 0 / 0 |
| May 24, 1989 | F4 | – | 0 / 0 |
| May 20, 1953 | F3 | – | 0 / 1 |
| Mar 22, 1991 | F3 | – | 0 / 0 |
| Mar 13, 1990 | F3 | – | 1 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Aug 11, 2010 | Flood | Ames | $50M |
| May 24, 1989 | Tornado | – | $25M |
| Jun 12, 2010 | Flood | Story City | $20M |
| May 21, 2024 | Tornado | Cambridge | $3M |
| Mar 13, 1990 | Tornado | – | $3M |
| Mar 22, 1991 | Tornado | – | $3M |
Source: NOAA Storm Events Database, county-based reports through Sep 22, 2025. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.
Flood insurance in Story County
Check your address flood zone ›National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.
Homes in Story County
Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 41,887 housing units.
Compare in Iowa
All 99 ›| Largest counties | Overall risk | Top hazard |
|---|---|---|
| Polk County | Inland flooding | |
| Linn County | Inland flooding | |
| Scott County | Inland flooding | |
| Johnson County | Tornado | |
| Black Hawk County | Inland flooding | |
| Woodbury County | Inland flooding | |
| Dallas County | Inland flooding | |
| Dubuque County | Inland flooding |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Polk County | 19 | |
| Marshall County | 18 | |
| Jasper County | 17 | |
| Boone County | 15 | |
| Hardin County | 16 | |
| Hamilton County | 19 |
Cities in Story County
Common questions about Story County
What is the biggest natural hazard in Story County?
Inland flooding has the highest expected yearly losses in Story County, about $16.4 million a year in FEMA's estimate. Tornado is second at $10.4 million.
How many federal disasters has Story County had?
Story County has been included in 20 federal disaster or emergency declarations for natural events since 1969, including 19 major disasters. The most recent was Severe Storms and Flooding in September 2026.
Is Story County a high-risk place to live?
Its overall rating is Relatively Low, 9th highest of 99 in Iowa. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.
Do I need flood insurance in Story County?
Standard home insurance does not cover flooding. About 1 in 333 homes in Story County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.
How many tornadoes has Story County had?
NOAA records list 64 tornadoes in Story County since 1950. The strongest was an F5 tornado on June 13, 1976. The weather service has also logged 325 hail reports and 117 floods here.
Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.