Cass County, IA
FEMA National Risk Index scores, disaster declarations & hazard data
Cass County has experienced 19 federally declared disasters since 1965, most recently Severe Storms, Straight-Line Winds, And Tornadoes in 2022. Its overall natural hazard risk is rated Relatively Low — lower risk than most US counties.
Cass County's highest-rated hazards are drought, cold wave, and hail, with its top risk rated "Relatively High" by FEMA's National Risk Index. NOAA records 34 storm events in the county over the past decade. Community vulnerability is relatively low (21st 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. Cass County has been designated in 19 declarations since 1965, covering 6 disaster types including flood (7), severe storm (6), biological (2).
| Year | Type | Event name |
|---|---|---|
| 2022 | Severe Storm | Severe Storms, Straight-Line Winds, And Tornadoes |
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2019 | Flood | Severe Storms And Flooding |
| 2010 | Severe Storm | Severe Winter Storms And Snowstorm |
| 2010 | Severe Storm | Severe Winter Storm |
| 2008 | Severe Storm | Severe Storms, Tornadoes, And Flooding |
| 2007 | Snowstorm | Snow |
| 2007 | Severe Storm | Severe Storms, Flooding, And Tornadoes |
| 2005 | Hurricane | Hurricane Katrina Evacuation |
Showing the 10 most recent of 19 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 | 40.6 | 0 | 0 | — |
| Inland Flooding | Relatively Low | 43.4 | 7 | 0 | $135K |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Very Low | 16.2 | — | — | — |
| Heat Wave | Relatively Low | 71.8 | 2 | 0 | — |
| Tornado | Relatively Moderate | 75.8 | 11 | 0 | $371K |
| Hurricane | Very Low | 17.6 | 0 | 0 | — |
| Hail | Relatively Moderate | 79.5 | 12 | 0 | — |
| Strong Wind | Relatively Moderate | 60.9 | 0 | 0 | — |
| Winter Weather | Relatively Low | 48.2 | 0 | 0 | — |
| Ice Storm | Relatively Low | 56.4 | — | — | — |
| Cold Wave | Relatively Moderate | 86.9 | — | — | — |
| Lightning | Very Low | 17.6 | 2 | 0 | $60K |
| Drought | Relatively High | 97.6 | 0 | 0 | — |
| Landslide | Relatively Low | 65.5 | 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
Cass County ranks in the 21st 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 | 21st | Very low |
| Socioeconomic status | 26th | Low |
| Household characteristics | 37th | Low |
| Racial & ethnic minority status | 9th | Very low |
| Housing type & transportation | 27th | 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 | 37th | Relatively Low |
| Risk to homes | 37th | Relatively Low |
| Buildings in direct exposure zone | 34.3% | — |
NOAA tracked 34 weather events in this county over 2016–2025: 18 in 2016–20 vs 16 in 2021–25 (-11% — 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 Cass County?
According to the FEMA National Risk Index, the highest-risk hazards in Cass County, Iowa are drought, cold wave, and hail. The county's overall natural hazard risk is rated Relatively Low — lower risk than most US counties.
Has Cass County received federal disaster declarations?
Yes. Cass County has received 19 federal disaster declarations since 1965, including declarations in 2022. The most common disaster type on record is flood (7 declarations).
Has Cass County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for Cass County since the start of 2024. Its most recent declaration on record is Severe Storms, Straight-Line Winds, And Tornadoes in 2022.
How does Cass County's natural hazard risk compare to nearby counties?
Among neighboring counties, Pottawattamie County, IA has the highest overall natural hazard risk (Relatively Low) and Adams County, IA has the lowest (Very Low). Cass County is rated Relatively Low overall.
How is Cass County's composite disaster risk index calculated?
Cass 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. Cass County's composite score of 60 means its overall natural hazard risk is higher than 60% of US counties.