Washington County, Iowa: Natural Disaster Risk and History
Washington County, Iowa has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 44.2 out of 100, higher than about 44% of US counties, with strong winds, hail and drought scoring highest of its 18 hazards and $14 million a year in expected losses.
OpenFEMA lists 13 federal disaster declarations that included Washington County since 1965, not counting 2 for COVID-19; the latest is DR-4557-IA (Severe Storms, declared 17 August 2020). NOAA's Storm Prediction Center recorded 25 tornadoes touching Washington County from 1950 to 2025.
Live weather alerts for Iowa All official warnings Latest FEMA declarations
Population 22,565 Buildings worth $7.1 billion Area 577 sq mi Risk rank in Iowa 33 of 99 FIPS 19183
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Strong wind | Relatively High | 90.9 | $2.1 million | about 6.2 a year | 236 |
| Hail | Relatively Moderate | 83.3 | $1.1 million | about 4.4 a year | 169 |
| Drought | Relatively Moderate | 79.0 | $869,030 | about 8.5 a year | 350 |
| Heat wave | Relatively Low | 64.7 | $715,715 | about 8.3 a year | 122 |
| Landslide | Very Low | 61.3 | $2,891 | about once every 6.9 years | — |
| Tornado | Relatively Low | 57.0 | $1.6 million | about once every 2.0 years | 22 |
| Wildfire | Very Low | 54.9 | $61,741 | rarer than once in 1,000 years | — |
| Winter weather | Relatively Low | 53.1 | $70,594 | about 14 a year | 258 |
| Lightning | Relatively Low | 48.6 | $219,725 | about 44 a year | 72,914 strikes |
| Inland flooding | Relatively Low | 48.4 | $6.2 million | about 1.7 a year | 47 |
| Ice storm | Relatively Low | 47.0 | $74,197 | about once every 2.8 years | 24 |
| Cold wave | Relatively Low | 45.8 | $799,799 | about 6.1 a year | 115 |
| Earthquake | Very Low | 35.6 | $114,102 | rarer than once in 1,000 years | — |
| Hurricane | Very Low | 20.1 | $5,979 | about once every 174 years | 2 |
| 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 13
Most common: Severe Storm 7, Flood 4, Severe Ice Storm 1, Hurricane 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1960s | 1 | Flood |
| 1990s | 4 | Flood ×3, Severe Storm |
| 2000s | 5 | Severe Storm ×3, Severe Ice Storm, Hurricane |
| 2010s | 2 | Severe Storm ×2 |
| 2020s | 1 | Severe Storm |
The last 10
Widest declarations that included Washington County
- Hurricane Katrina Evacuation (2005, EM-3239-IA): 99 Iowa counties designated.
- Severe Storms & Flooding (1993, DR-996-IA): 99 Iowa counties designated.
- Severe Storms, Tornadoes, and Flooding (2008, DR-1763-IA): 85 Iowa 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. Iowa also had 7 statewide declarations with no county list.
Tornado record since 1950 25
| Tornadoes touching the county | 25 |
|---|---|
| Strongest-rated | (E)F4 ×1 |
| Peak month | May (10) |
| Deadliest | 15 May 1998, F3, 47 mi path, 0 killed, 47 injured |
| Longest path | 3 Apr 1981, F0, 103.5 mi path |
| Most recent | 24 May 2024, EF1, 18.3 mi path |
| Deaths / injuries on those paths | 0 / 52 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 4 | 11 | 7 | 2 | 1 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 2 | 3 | 5 | 2 | 6 | 4 | 3 |
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 Washington County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Washington County (this page) | — | Relatively Low | 44.2 | Strong wind |
| Keokuk County | 38 km | Very Low | 21.9 | Drought |
| Johnson County | 39 km | Relatively Moderate | 87.4 | Strong wind |
| Jefferson County | 39 km | Very Low | 27.1 | Drought |
| Louisa County | 40 km | Very Low | 17.5 | Drought |
| Henry County | 41 km | Very Low | 30.9 | Heat wave |
Nearest by distance between county centres. Every county in Iowa, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Moderate 41.7 |
|---|---|
| Community resilience | Very High 90.3 |
| Community risk factor | 1.05 |
| Expected annual loss, all hazards | $14 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 Washington County's main hazards
- Right now: National Weather Service alerts for Iowa · all official warnings on Global Incident Tracker.
- Strong wind: Power outages now
- Hail: Weather alerts for Iowa
- Drought: Drought monitor for Iowa
- 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 Washington County
What natural disasters is Washington County, Iowa most at risk from?
Washington County, Iowa has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 44.2 out of 100, higher than about 44% of US counties, with strong winds, hail and drought scoring highest of its 18 hazards and $14 million a year in expected losses.
How many federal disaster declarations has Washington County had?
OpenFEMA lists 13 federal disaster declarations that included Washington County since 1965, not counting 2 for COVID-19; the latest is DR-4557-IA (Severe Storms, declared 17 August 2020). Another 7 Iowa declarations were made statewide without a county list.
How many tornadoes have hit Washington County?
NOAA's Storm Prediction Center recorded 25 tornadoes touching Washington County from 1950 to 2025. The deadliest: 15 May 1998, F3, 47 mi path, 0 killed, 47 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.