Woodbury County, Iowa Natural Disaster Risk
FEMA National Risk Index assessment · IA
MediumComposite Risk Score
National percentile: 83th
Woodbury County faces medium composite natural disaster risk (NRI Risk Index score 83.3, 83th national percentile), driven primarily by tornado and hail exposure. Expected annual loss across all 18 hazard types is $51M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Woodbury County is medium, with a National Risk Index score of 83.3 out of 100 — placing it in the 83rd national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in tornado (violently rotating columns of air capable of catastrophic local damage) at High risk — $16M in expected annual loss and about 0.71 events per year; hail (ice stones from severe thunderstorms that damage property and crops) at High risk — $3M in expected annual loss and about 6.02 events per year; and drought (extended dry periods that stress water supplies and agriculture) at Medium risk — $2M in expected annual loss and about 34.75 events per year. Across all hazards, FEMA estimates $51M in expected annual loss for a population of 106K.
Beyond physical exposure, Woodbury County has a 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: Woodbury County has received 18 federal disaster declarations since 1965, including 7 for flood events and 5 for severe storm events. The most recent was Severe Winter Storm (winter storm), declared in May 2025.
Among 99 Iowa counties, Woodbury County ranks #5 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Tornado | High | 0.71 / yr | $16M |
| Hail | High | 6.02 / yr | $3M |
| Drought | Medium | 34.75 / yr | $2M |
| Wildfire | Low | 0.00 / yr | $932K |
| Cold Wave | Medium | 6.47 / yr | $6M |
| Winter Weather | High | 14.84 / yr | $293K |
| Ice Storm | High | 0.91 / yr | $631K |
| Strong Wind | High | 4.20 / yr | $2M |
| Landslide | Low | 0.45 / yr | $26K |
| Heat Wave | Medium | 6.53 / yr | $2M |
| Riverine Flood | Medium | 2.21 / yr | $18M |
| Lightning | Low | 41.90 / yr | $250K |
| Earthquake | Very Low | 0.00 / yr | $84K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Woodbury County has received 18 federal disaster declarations since 1965, most recently Severe Winter Storm in May 2025. Most frequent causes: Flood (7), Severe Storm (5), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| May 2025 | Winter Storm | Severe Winter Storm |
| June 2024 | Severe Storm | Severe Storms, Flooding, Straight-Line Winds, and Tornadoes |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| March 2019 | Flood | Severe Storms and Flooding |
| August 2018 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| July 2014 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| June 2011 | Flood | Flooding |
| February 2010 | Severe Storm | Severe Winter Storms and Snowstorm |
| March 2007 | Snowstorm | Snow |
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 Woodbury County?
Woodbury County has a composite FEMA National Risk Index score of 83.3 out of 100, placing it in the Medium category and the 83th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Woodbury County?
The three highest-rated hazards are Tornado (High, $16M EAL), Hail (High, $3M EAL), Drought (Medium, $2M EAL). These account for most of the county's expected annual losses.
How does Woodbury County compare to other Iowa counties?
Woodbury County ranks #5 of 99 Iowa counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Woodbury County had?
FEMA records 18 federal disaster declarations for Woodbury County since 1965, most often 7 for flood events and 5 for severe storm events. The most recent was Severe Winter Storm, declared in May 2025.
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. Woodbury County's $51M EAL is a statistical average, not a guarantee for any specific year or address.