Harrison County, IA
FEMA National Risk Index scores, disaster declarations & hazard data
Harrison County has experienced 24 federally declared disasters since 1965, most recently Severe Winter Storm in 2025. Its overall natural hazard risk is rated Very Low — among the lowest-risk counties in the country.
Harrison County's highest-rated hazards are drought, hail, and landslide, with its top risk rated "Relatively Moderate" by FEMA's National Risk Index. Recorded storm events have increased 41% over the past five years compared to the prior five-year period. Community vulnerability is relatively low (4th percentile nationally), indicating stronger recovery capacity than most US counties.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Harrison County has been designated in 24 declarations since 1965, covering 7 disaster types including severe storm (9), flood (9), biological (2).
| Year | Type | Event name |
|---|---|---|
| 2025 | Winter Storm | Severe Winter Storm |
| 2024 | Severe Storm | Severe Storms, Tornadoes, And Flooding |
| 2024 | Severe Storm | Severe Storms, Flooding, Straight-Line Winds, And Tornadoes |
| 2024 | Tornado | Severe Storms And Tornadoes |
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2019 | Flood | Severe Storms And Flooding |
| 2011 | Flood | Flooding |
| 2010 | Severe Storm | Severe Winter Storms And Snowstorm |
| 2010 | Severe Storm | Severe Winter Storm |
Showing the 10 most recent of 24 total declarations since 1965.
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Very Low | 59.8 | 0 | 0 | — |
| Inland Flooding | Relatively Low | 37 | 8 | 0 | $2.9M |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Very Low | 11.8 | — | — | — |
| Heat Wave | Very Low | 19.4 | 5 | 0 | — |
| Tornado | Relatively Low | 60.1 | 12 | 0 | — |
| Hurricane | No Rating | 0 | 0 | 0 | — |
| Hail | Relatively Moderate | 86.4 | 28 | 0 | — |
| Strong Wind | Relatively Moderate | 55.9 | 0 | 0 | — |
| Winter Weather | Relatively Low | 36 | 0 | 0 | — |
| Ice Storm | Relatively Low | 53.7 | — | — | — |
| Cold Wave | Relatively Low | 29.1 | — | — | — |
| Lightning | Very Low | 16.4 | 0 | 0 | — |
| Drought | Relatively Moderate | 86.4 | 0 | 0 | — |
| Landslide | Relatively Low | 84.6 | 0 | 0 | — |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Not Applicable | — | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
Harrison County ranks in the 4th percentile (Very low) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 4th | Very low |
| Socioeconomic status | 5th | Very low |
| Household characteristics | 6th | Very low |
| Racial & ethnic minority status | 5th | Very low |
| Housing type & transportation | 20th | Very low |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 49th | Relatively Moderate |
| Risk to homes | 52nd | Relatively Moderate |
| Buildings in direct exposure zone | 43.9% | — |
NOAA tracked 53 weather events in this county over 2016–2025: 22 in 2016–20 vs 31 in 2021–25 (+41% — frequency increasing).
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in Harrison County?
According to the FEMA National Risk Index, the highest-risk hazards in Harrison County, Iowa are drought, hail, and landslide. The county's overall natural hazard risk is rated Very Low — among the lowest-risk counties in the country.
Has Harrison County received federal disaster declarations?
Yes. Harrison County has received 24 federal disaster declarations since 1965, including declarations in 2025. The most common disaster type on record is severe storm (9 declarations).
Has Harrison County had any FEMA disaster declarations in 2024, 2025, or 2026?
Yes. Recent federal disaster declarations for Harrison County include Severe Winter Storm (2025), Severe Storms, Tornadoes, And Flooding (2024), Severe Storms, Flooding, Straight-Line Winds, And Tornadoes (2024), Severe Storms And Tornadoes (2024). See the declarations table above for the full history since 1965.
How does Harrison County's natural hazard risk compare to nearby counties?
Among neighboring counties, Douglas County, NE has the highest overall natural hazard risk (Relatively High) and Burt County, NE has the lowest (Very Low). Harrison County is rated Very Low overall.
How is Harrison County's composite disaster risk index calculated?
Harrison County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. Harrison County's composite score of 31 means its overall natural hazard risk is higher than 31% of US counties.