Benton County, Iowa Natural Disaster Risk
FEMA National Risk Index assessment · IA
Very LowComposite Risk Score
National percentile: 29th
Benton County faces very low composite natural disaster risk (NRI Risk Index score 28.8, 29th national percentile), driven primarily by drought and strong wind exposure. Expected annual loss across all 18 hazard types is $16M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Benton County carries a very low composite natural disaster risk, with a National Risk Index score of 28.8 out of 100 — placing it in the 29th national percentile and among the lowest-risk counties in the country. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by drought (extended dry periods that stress water supplies and agriculture) at Medium risk — $2M in expected annual loss and about 15.49 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at Medium risk — $2M in expected annual loss and about 5.55 events per year; and hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $1M in expected annual loss and about 4.73 events per year. Across all hazards, FEMA estimates $16M in expected annual loss for a population of 26K.
Beyond physical exposure, Benton County has a very low social vulnerability rating (how susceptible the population is to harm) and a very high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
The federal record bears this out: Benton County has received 18 federal disaster declarations since 1965, including 8 for flood events and 7 for severe storm events. The most recent was Severe Storms (severe storm), declared in August 2020.
Among 99 Iowa counties, Benton County ranks #67 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | Medium | 15.49 / yr | $2M |
| Strong Wind | Medium | 5.55 / yr | $2M |
| Hail | Medium | 4.73 / yr | $1M |
| Winter Weather | Low | 16.16 / yr | $128K |
| Ice Storm | Low | 0.31 / yr | $113K |
| Tornado | Low | 0.67 / yr | $2M |
| Landslide | Very Low | 0.10 / yr | $1K |
| Riverine Flood | Low | 1.18 / yr | $8M |
| Wildfire | Very Low | 0.00 / yr | $35K |
| Cold Wave | Very Low | 7.89 / yr | $423K |
| Earthquake | Very Low | 0.00 / yr | $50K |
| Heat Wave | Very Low | 6.00 / yr | $79K |
| Lightning | Very Low | 44.07 / yr | $85K |
| Hurricane | Very Low | 0.01 / yr | $4K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Benton County has received 18 federal disaster declarations since 1965, most recently Severe Storms in August 2020. Most frequent causes: Flood (8), Severe Storm (7), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| August 2020 | Severe Storm | Severe Storms |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| October 2016 | Flood | Severe Storms and Flooding |
| July 2013 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| July 2013 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| August 2011 | Severe Storm | Severe Storms, Straight-Line Winds, and Flooding |
| May 2008 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| March 2007 | Severe Storm | Severe Winter Storms |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
Showing the 10 most recent of 18 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Benton County?
Benton County has a composite FEMA National Risk Index score of 28.8 out of 100, placing it in the Very Low category and the 29th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Benton County?
The three highest-rated hazards are Drought (Medium, $2M EAL), Strong Wind (Medium, $2M EAL), Hail (Medium, $1M EAL). These account for most of the county's expected annual losses.
How does Benton County compare to other Iowa counties?
Benton County ranks #67 of 99 Iowa counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Benton County had?
FEMA records 18 federal disaster declarations for Benton County since 1965, most often 8 for flood events and 7 for severe storm events. The most recent was Severe Storms, declared in August 2020.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Benton County's $16M EAL is a statistical average, not a guarantee for any specific year or address.