Defiance County, Ohio: Natural Disaster Risk and History
Defiance County, Ohio has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 41.9 out of 100, higher than about 41% of US counties, with hail, tornadoes and inland (river and flash) flooding scoring highest of its 18 hazards and $16 million a year in expected losses.
OpenFEMA lists 6 federal disaster declarations that included Defiance County since 1977, not counting 2 for COVID-19; the latest is EM-3346-OH (Severe Storms, declared 30 June 2012). NOAA's Storm Prediction Center recorded 12 tornadoes touching Defiance County from 1950 to 2025.
Live weather alerts for Ohio All official warnings Latest FEMA declarations
Population 38,229 Buildings worth $9.1 billion Area 418 sq mi Risk rank in Ohio 63 of 88 FIPS 39039
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Hail | Relatively Low | 64.9 | $537,175 | about 3.4 a year | 127 |
| Tornado | Relatively Low | 63.7 | $2.4 million | about once every 4.4 years | 8 |
| Inland flooding | Relatively Low | 59.4 | $11 million | about once every 2.0 years | 14 |
| Ice storm | Relatively Low | 54.6 | $124,650 | about 1.4 a year | 97 |
| Strong wind | Relatively Moderate | 53.5 | $729,996 | about 4.4 a year | 166 |
| Earthquake | Very Low | 52.6 | $377,635 | about once every 741 years | — |
| Landslide | Very Low | 40.9 | $837 | about once every 13 years | — |
| Cold wave | Relatively Low | 31.6 | $543,607 | about 3.3 a year | 63 |
| Lightning | Relatively Low | 31.3 | $136,103 | about 39 a year | 76,743 strikes |
| Winter weather | Relatively Low | 31.2 | $37,421 | about 1 a year | 190 |
| Drought | Very Low | 27.6 | $21,072 | about once every 2.5 years | 42 |
| Heat wave | Very Low | 27.4 | $137,848 | about 4.3 a year | 68 |
| Hurricane | Very Low | 27.0 | $13,431 | about once every 90 years | 2 |
| Wildfire | Very Low | 6.9 | $2,586 | 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 6
Most common: Severe Storm 2, Snowstorm 2, Hurricane 1, Flood 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 2 | Snowstorm ×2 |
| 1980s | 1 | Flood |
| 2000s | 2 | Hurricane, Severe Storm |
| 2010s | 1 | Severe Storm |
The last 6
Widest declarations that included Defiance County
- Severe Storms (2012, EM-3346-OH): 88 Ohio counties designated.
- Hurricane Katrina Evacuation (2005, EM-3250-OH): 88 Ohio counties designated.
- Severe Storms and Flooding (2004, DR-1556-OH): 88 Ohio 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. Ohio also had 3 statewide declarations with no county list.
Tornado record since 1950 12
| Tornadoes touching the county | 12 |
|---|---|
| Strongest-rated | (E)F4 ×1 |
| Peak month | July (5) |
| Deadliest | 10 Nov 2002, F4, 52.8 mi path, 4 killed, 17 injured |
| Longest path | 10 Nov 2002, F4, 52.8 mi path, 4 killed, 17 injured |
| Most recent | 29 Jul 2023, EF1, 0.7 mi path |
| Deaths / injuries on those paths | 4 / 17 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 6 | 1 | 4 | 0 | 1 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 1 | 3 | 2 | 0 | 2 | 2 | 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 Defiance County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Defiance County (this page) | — | Very Low | 41.9 | Hail |
| Paulding County | 24 km | Very Low | 21.2 | Hail |
| Williams County | 28 km | Relatively Low | 44.4 | Strong wind |
| Henry County | 35 km | Very Low | 33.8 | Hail |
| Fulton County | 43 km | Very Low | 33.6 | Drought |
| DeKalb County, IN | 43 km | Very Low | 41.3 | Strong wind |
Nearest by distance between county centres. Every county in Ohio, ranked.
Vulnerability and resilience
| Social vulnerability | Very Low 19.3 |
|---|---|
| Community resilience | Very High 89.7 |
| Community risk factor | 0.87 |
| Expected annual loss, all hazards | $16 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 Defiance County's main hazards
- Right now: National Weather Service alerts for Ohio · all official warnings on Global Incident Tracker.
- Hail: Weather alerts for Ohio
- Tornado: Is there a tornado warning now?
- Inland flooding: Flood safety: why shallow water kills · Floods recorded
- 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 Defiance County
What natural disasters is Defiance County, Ohio most at risk from?
Defiance County, Ohio has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 41.9 out of 100, higher than about 41% of US counties, with hail, tornadoes and inland (river and flash) flooding scoring highest of its 18 hazards and $16 million a year in expected losses.
How many federal disaster declarations has Defiance County had?
OpenFEMA lists 6 federal disaster declarations that included Defiance County since 1977, not counting 2 for COVID-19; the latest is EM-3346-OH (Severe Storms, declared 30 June 2012). Another 3 Ohio declarations were made statewide without a county list.
How many tornadoes have hit Defiance County?
NOAA's Storm Prediction Center recorded 12 tornadoes touching Defiance County from 1950 to 2025. The deadliest: 10 Nov 2002, F4, 52.8 mi path, 4 killed, 17 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.