Plymouth County, IA
FEMA National Risk Index scores, disaster declarations & hazard data
Plymouth County has experienced 16 federally declared disasters since 1965, most recently Severe Storms, Flooding, Straight-Line Winds, And Tornadoes in 2024. Its overall natural hazard risk is rated Relatively Low — lower risk than most US counties.
Plymouth County's highest-rated hazards are hail, drought, and landslide, with its top risk rated "Relatively Moderate" by FEMA's National Risk Index. Recorded storm events have decreased 34% over the past five years compared to the prior five-year period. Community vulnerability is relatively low (6th 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. Plymouth County has been designated in 16 declarations since 1965, covering 7 disaster types including flood (6), severe storm (4), biological (2).
| Year | Type | Event name |
|---|---|---|
| 2024 | Severe Storm | Severe Storms, Flooding, Straight-Line Winds, And Tornadoes |
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2019 | Flood | Severe Storms And Flooding |
| 2014 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, And Flooding |
| 2013 | Severe Storm | Severe Storms, Tornadoes, And Flooding |
| 2010 | Severe Storm | Severe Winter Storms And Snowstorm |
| 2007 | Snowstorm | Snow |
| 2005 | Hurricane | Hurricane Katrina Evacuation |
| 1996 | Severe Storm | Severe Storms, And Flooding |
Showing the 10 most recent of 16 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 | Relatively Low | 70.5 | 0 | 0 | — |
| Inland Flooding | Relatively Low | 45.2 | 79 | 0 | $3.9M |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Very Low | 14.4 | — | — | — |
| Heat Wave | Relatively Low | 41.7 | 20 | 0 | — |
| Tornado | Relatively Moderate | 77.4 | 5 | 0 | $50K |
| Hurricane | Not Applicable | — | 0 | 0 | — |
| Hail | Relatively Moderate | 93.5 | 62 | 0 | $206K |
| Strong Wind | Relatively Low | 42.9 | 0 | 0 | — |
| Winter Weather | Relatively Moderate | 75.8 | 0 | 0 | — |
| Ice Storm | Relatively Moderate | 70.3 | — | — | — |
| Cold Wave | Relatively Low | 52.3 | — | — | — |
| Lightning | Relatively Low | 37.2 | 0 | 0 | — |
| Drought | Relatively Moderate | 90.3 | 0 | 0 | — |
| Landslide | Relatively Low | 81.1 | 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
Plymouth County ranks in the 6th 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 | 6th | Very low |
| Socioeconomic status | 2nd | Very low |
| Household characteristics | 47th | Low |
| Racial & ethnic minority status | 30th | Low |
| Housing type & transportation | 12th | 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 | 44th | Relatively Moderate |
| Risk to homes | 54th | Relatively Moderate |
| Buildings in direct exposure zone | 38.9% | — |
NOAA tracked 166 weather events in this county over 2016–2025: 100 in 2016–20 vs 66 in 2021–25 (-34% — frequency decreasing).
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 Plymouth County?
According to the FEMA National Risk Index, the highest-risk hazards in Plymouth County, Iowa are hail, drought, and landslide. The county's overall natural hazard risk is rated Relatively Low — lower risk than most US counties.
Has Plymouth County received federal disaster declarations?
Yes. Plymouth County has received 16 federal disaster declarations since 1965, including declarations in 2024. The most common disaster type on record is flood (6 declarations).
Has Plymouth County had any FEMA disaster declarations in 2024, 2025, or 2026?
Yes. Recent federal disaster declarations for Plymouth County include Severe Storms, Flooding, Straight-Line Winds, And Tornadoes (2024). See the declarations table above for the full history since 1965.
How does Plymouth County's natural hazard risk compare to nearby counties?
Among neighboring counties, Woodbury County, IA has the highest overall natural hazard risk (Relatively Moderate) and Dixon County, NE has the lowest (Very Low). Plymouth County is rated Relatively Low overall.
How is Plymouth County's composite disaster risk index calculated?
Plymouth 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. Plymouth County's composite score of 49 means its overall natural hazard risk is higher than 49% of US counties.