Marion County, Iowa Natural Disaster Risk
FEMA National Risk Index assessment · IA
Very LowComposite Risk Score
National percentile: 34th
Marion County faces very low composite natural disaster risk (NRI Risk Index score 34.4, 34th national percentile), driven primarily by drought and landslide exposure. Expected annual loss across all 18 hazard types is $14M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Marion County carries a very low composite natural disaster risk, with a National Risk Index score of 34.4 out of 100 — placing it in the 34th 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 6.80 events per year; landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $10K in expected annual loss and about 0.28 events per year; and tornado (violently rotating columns of air capable of catastrophic local damage) at Medium risk — $3M in expected annual loss and about 0.48 events per year. Across all hazards, FEMA estimates $14M in expected annual loss for a population of 33K.
Beyond physical exposure, Marion 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.
History supports the rating: Marion County has received 19 federal disaster declarations since 1965, including 9 for flood events and 5 for severe storm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 99 Iowa counties, Marion County ranks #52 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | Medium | 6.80 / yr | $2M |
| Landslide | Low | 0.28 / yr | $10K |
| Tornado | Medium | 0.48 / yr | $3M |
| Heat Wave | Low | 7.16 / yr | $798K |
| Hail | Low | 5.53 / yr | $397K |
| Wildfire | Very Low | 0.00 / yr | $64K |
| Strong Wind | Low | 5.76 / yr | $655K |
| Ice Storm | Low | 0.73 / yr | $77K |
| Riverine Flood | Low | 3.43 / yr | $7M |
| Lightning | Low | 44.58 / yr | $166K |
| Earthquake | Very Low | 0.00 / yr | $108K |
| Winter Weather | Low | 12.53 / yr | $40K |
| Cold Wave | Low | 5.21 / yr | $433K |
| Hurricane | Very Low | 0.01 / yr | $2K |
| 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
Marion County has received 19 federal disaster declarations since 1965, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Flood (9), Severe Storm (5), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2018 | Severe Storm | Severe Storm and Tornadoes |
| July 2015 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| May 2013 | Flood | Severe Storms, Straight-Line Winds, and Flooding |
| July 2010 | Severe Storm | Severe Storms, Flooding, and Tornadoes |
| May 2008 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| January 2008 | Severe Ice Storm | Severe Winter Storm |
| March 2007 | Severe Storm | Severe Winter Storms |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
Showing the 10 most recent of 19 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Marion County?
Marion County has a composite FEMA National Risk Index score of 34.4 out of 100, placing it in the Very Low category and the 34th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Marion County?
The three highest-rated hazards are Drought (Medium, $2M EAL), Landslide (Low, $10K EAL), Tornado (Medium, $3M EAL). These account for most of the county's expected annual losses.
How does Marion County compare to other Iowa counties?
Marion County ranks #52 of 99 Iowa counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Marion County had?
FEMA records 19 federal disaster declarations for Marion County since 1965, most often 9 for flood events and 5 for severe storm events. The most recent was Covid-19 Pandemic, declared in March 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. Marion County's $14M EAL is a statistical average, not a guarantee for any specific year or address.