Hamilton County, Indiana: Natural Disaster Risk and History
Hamilton County, Indiana has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 88.8 out of 100, higher than about 88% of US counties, with tornadoes, hail and winter storms scoring highest of its 18 hazards and $129 million a year in expected losses.
OpenFEMA lists 19 federal disaster declarations that included Hamilton County since 1965, not counting 2 for COVID-19; the latest is DR-4933-IN (Severe Storms, Straight-Line Winds, Tornadoes, and Flooding, declared 25 August 2026). NOAA's Storm Prediction Center recorded 30 tornadoes touching Hamilton County from 1950 to 2025.
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Population 347,343 Buildings worth $89 billion Area 407 sq mi Risk rank in Indiana 5 of 92 FIPS 18057
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Tornado | Relatively High | 96.8 | $30 million | about once every 3.2 years | 20 |
| Hail | Relatively Moderate | 93.5 | $4.0 million | about 4.4 a year | 167 |
| Winter weather | Relatively High | 91.2 | $739,733 | about 1 a year | 195 |
| Inland flooding | Relatively Moderate | 91.1 | $73 million | about 1.8 a year | 51 |
| Cold wave | Relatively Moderate | 86.1 | $9.0 million | about 3.4 a year | 65 |
| Heat wave | Relatively Moderate | 86.0 | $3.6 million | about 4.3 a year | 63 |
| Earthquake | Relatively Low | 84.9 | $4.7 million | about once every 541 years | — |
| Lightning | Relatively High | 83.9 | $1.5 million | about 46 a year | 280,458 strikes |
| Strong wind | Relatively Moderate | 80.8 | $2.3 million | about 4.8 a year | 181 |
| Ice storm | Relatively Moderate | 73.4 | $447,520 | about once a year | 67 |
| Drought | Relatively Low | 51.5 | $266,754 | about 1.4 a year | 42 |
| Landslide | Very Low | 47.6 | $1,968 | about once every 11 years | — |
| Hurricane | Very Low | 25.6 | $16,385 | about once every 87 years | 2 |
| Wildfire | Very Low | 20.3 | $12,898 | rarer than once in 1,000 years | — |
| Avalanche | Not Applicable | — | — | — | — |
| Coastal flooding | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 19
Most common: Severe Storm 8, Flood 4, Snowstorm 3, Winter Storm 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1960s | 1 | Tornado |
| 1990s | 4 | Flood ×2, Snowstorm, Severe Ice Storm |
| 2000s | 10 | Severe Storm ×7, Snowstorm ×2, Hurricane |
| 2010s | 1 | Severe Storm |
| 2020s | 3 | Flood ×2, Winter Storm |
The last 10
Widest declarations that included Hamilton County
- Severe Winter Storm (2026, EM-3641-IN): 92 Indiana counties designated.
- Hurricane Katrina Evacuation (2005, EM-3238-IN): 92 Indiana counties designated.
- Severe Winter Storms and Flooding (2005, DR-1573-IN): 87 Indiana counties designated.
Named storms in its declarations: Hurricane Katrina (2005).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Indiana also had 3 statewide declarations with no county list.
Tornado record since 1950 30
| Tornadoes touching the county | 30 |
|---|---|
| Strongest-rated | (E)F4 ×1 |
| Peak month | June (6) |
| Deadliest | 11 Apr 1965, F4, 45.7 mi path, 28 killed, 123 injured |
| Longest path | 11 Apr 1965, F4, 45.7 mi path, 28 killed, 123 injured |
| Most recent | 2 Apr 2025, EF1, 6.6 mi path |
| Deaths / injuries on those paths | 28 / 130 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 9 | 14 | 5 | 1 | 1 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 4 | 8 | 3 | 7 | 3 | 3 | 2 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Hamilton County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Hamilton County (this page) | — | Relatively Moderate | 88.8 | Tornado |
| Tipton County | 27 km | Very Low | 8.9 | Drought |
| Madison County | 30 km | Relatively Low | 77.3 | Strong wind |
| Marion County | 33 km | Relatively High | 97.5 | Tornado |
| Boone County | 36 km | Relatively Low | 43.2 | Hail |
| Hancock County | 36 km | Relatively Low | 44.0 | Tornado |
Nearest by distance between county centres. Every county in Indiana, ranked.
Vulnerability and resilience
| Social vulnerability | Very Low 10.6 |
|---|---|
| Community resilience | Very High 93.1 |
| Community risk factor | 0.62 |
| Expected annual loss, all hazards | $129 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Hamilton County's main hazards
- Right now: National Weather Service alerts for Indiana · all official warnings on Global Incident Tracker.
- Tornado: Is there a tornado warning now?
- Hail: Weather alerts for Indiana
- Winter weather: Power outages now · Carbon monoxide in winter
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Hamilton County
What natural disasters is Hamilton County, Indiana most at risk from?
Hamilton County, Indiana has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 88.8 out of 100, higher than about 88% of US counties, with tornadoes, hail and winter storms scoring highest of its 18 hazards and $129 million a year in expected losses.
How many federal disaster declarations has Hamilton County had?
OpenFEMA lists 19 federal disaster declarations that included Hamilton County since 1965, not counting 2 for COVID-19; the latest is DR-4933-IN (Severe Storms, Straight-Line Winds, Tornadoes, and Flooding, declared 25 August 2026). Another 3 Indiana declarations were made statewide without a county list.
How many tornadoes have hit Hamilton County?
NOAA's Storm Prediction Center recorded 30 tornadoes touching Hamilton County from 1950 to 2025. The deadliest: 11 Apr 1965, F4, 45.7 mi path, 28 killed, 123 injured (deaths and injuries are for the whole path).
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.