Calhoun County, Iowa
Natural disaster risk, federal disaster history and flood insurance facts.
Calhoun County, Iowa has a relatively low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 55% of US counties. It ranks 32nd of 99 counties in Iowa. The costliest hazards here are drought, tornadoes and inland flooding. FEMA estimates about $13 million a year in expected losses, or roughly $1,344 per resident. Since 1979 it has been included in 16 federal disaster or emergency declarations for natural events (15 major disasters). The most recent was in May 2024 (severe storms, tornadoes and flooding). Only 3 homes here carry federal flood insurance.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Calhoun County
- Check local water restrictions.
- Choose drought-tolerant plants.
- 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 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.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Drought | 97.1 | $4M | ||
| Tornado | 73.6 | $3M | ||
| Inland flooding | 20.6 | $2M | ||
| Hail | 92.8 | $2M | ||
| Cold wave | 60.3 | $1M | ||
| Strong wind | 65.2 | $795K | ||
| Winter weather | 61.7 | $91K | ||
| Ice storm | 46.6 | $69K | ||
| Lightning | 20.2 | $65K | ||
| Heat wave | 17.7 | $46K | ||
| Earthquake | 14.6 | $15K | ||
| Hurricane | 14.7 | $3K | ||
| Wildfire | 8.5 | $3K | ||
| Landslide | 20.5 | $116 |
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 moderate 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 Calhoun County. 2020s bar runs to November 2026.
By type
Most recent
Show all 16
Iowa also had 11 statewide declarations that did not name single counties.
Storm history since 1953
Tornado risk by county ›The National Weather Service has logged 360 storm reports in Calhoun County since 1953, with 4 deaths and 33 injuries and about $96.8 million in reported damage. The strongest on record here was an F4 tornado on June 28, 1979.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Jun 28, 1979 | F4 | – | 26 / 3 |
| Jun 9, 1954 | F4 | – | 0 / 1 |
| May 5, 1965 | F4 | – | 0 / 0 |
| Jul 14, 2021 | EF3 | Lake City | 0 / 0 |
| Jun 7, 1953 | F3 | – | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Jun 28, 1979 | Tornado | – | $25M |
| Jun 12, 2010 | Flood | Knoke | $20M |
| Aug 9, 2009 | Hail | Yetter | $15M |
| Aug 9, 2009 | Hail | Rockwell City | $15M |
| Aug 9, 2009 | Thunderstorm Wind | Somers | $6M |
| Jul 14, 2021 | Tornado | Lake City | $3M |
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 Calhoun 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 Calhoun 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; 4,798 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 |
|---|---|---|
| Webster County | 18 | |
| Buena Vista County | 20 | |
| Carroll County | 14 | |
| Sac County | 17 | |
| Greene County | 17 | |
| Pocahontas County | 20 |
Common questions about Calhoun County
What is the biggest natural hazard in Calhoun County?
Drought has the highest expected yearly losses in Calhoun County, about $3.7 million a year in FEMA's estimate. Tornado is second at $2.8 million.
How many federal disasters has Calhoun County had?
Calhoun County has been included in 16 federal disaster or emergency declarations for natural events since 1979, including 15 major disasters. The most recent was Severe Storms, Tornadoes, and Flooding in May 2024.
Is Calhoun County a high-risk place to live?
Its overall rating is Relatively Low, 32nd 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 Calhoun County?
Standard home insurance does not cover flooding. About 1 in 1000 homes in Calhoun 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 Calhoun County had?
NOAA records list 37 tornadoes in Calhoun County since 1950. The strongest was an F4 tornado on June 28, 1979. The weather service has also logged 132 hail reports and 30 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.