Union County, Iowa
Natural disaster risk, federal disaster history and flood insurance facts.
Union County, Iowa has a relatively low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 50% of US counties. It ranks 27th of 99 counties in Iowa. The costliest hazards here are cold waves, inland flooding and drought. FEMA estimates about $13 million a year in expected losses, or roughly $1,033 per resident. Since 1969 it has been included in 19 federal disaster or emergency declarations for natural events (17 major disasters). The most recent was in May 2024 (severe storms and tornadoes). Only 14 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $133,000 on 14 claims here.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Union County
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
- 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.
- Check local water restrictions.
- Choose drought-tolerant plants.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Cold wave | 84.5 | $4M | ||
| Inland flooding | 30.1 | $3M | ||
| Drought | 95.4 | $2M | ||
| Heat wave | 82.7 | $1M | ||
| Tornado | 57.1 | $1M | ||
| Hail | 74.2 | $528K | ||
| Strong wind | 54.1 | $484K | ||
| Lightning | 19.4 | $52K | ||
| Winter weather | 43.8 | $41K | ||
| Wildfire | 49.8 | $37K | ||
| Ice storm | 36.9 | $36K | ||
| Earthquake | 24.2 | $32K | ||
| Landslide | 62.8 | $3K | ||
| Hurricane | 11.0 | $2K |
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 relatively high and community resilience is relatively high in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included Union County. 2020s bar runs to November 2026.
By type
Most recent
Show all 19
Iowa also had 11 statewide declarations that did not name single counties.
Storm history since 1956
Tornado risk by county ›The National Weather Service has logged 393 storm reports in Union County since 1956, with 0 deaths and 9 injuries and about $65.8 million in reported damage. The strongest on record here was an F4 tornado on May 24, 1989.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| May 24, 1989 | F4 | – | 0 / 0 |
| May 27, 1995 | F4 | Creston To | 2 / 0 |
| Apr 8, 1999 | F4 | Creston | 1 / 0 |
| Mar 29, 1979 | F3 | – | 2 / 0 |
| Apr 14, 2012 | EF2 | Cromwell | 2 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| May 24, 1989 | Tornado | – | $25M |
| Jun 12, 2010 | Flood | Spaulding | $20M |
| Apr 14, 2012 | Tornado | Cromwell | $5M |
| May 27, 1995 | Tornado | Creston To | $3M |
| Mar 29, 1979 | Tornado | – | $3M |
| Apr 8, 1999 | Tornado | Creston | $2M |
Source: NOAA Storm Events Database, county-based reports through Sep 16, 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 Union 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 Union 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; 5,785 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 |
|---|---|---|
| Madison County | 18 | |
| Clarke County | 14 | |
| Decatur County | 12 | |
| Adair County | 15 | |
| Taylor County | 12 | |
| Ringgold County | 18 | |
| Adams County | 15 |
Common questions about Union County
What is the biggest natural hazard in Union County?
Cold wave has the highest expected yearly losses in Union County, about $3.8 million a year in FEMA's estimate. Inland flooding is second at $2.8 million.
How many federal disasters has Union County had?
Union County has been included in 19 federal disaster or emergency declarations for natural events since 1969, including 17 major disasters. The most recent was Severe Storms and Tornadoes in May 2024.
Is Union County a high-risk place to live?
Its overall rating is Relatively Low, 27th 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 Union County?
Standard home insurance does not cover flooding. About 1 in 500 homes in Union 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 Union County had?
NOAA records list 42 tornadoes in Union County since 1950. The strongest was an F4 tornado on May 24, 1989. The weather service has also logged 120 hail reports and 31 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.