Buchanan County, Iowa Natural Disaster Risk
FEMA National Risk Index assessment · IA
Very LowComposite Risk Score
National percentile: 24th
Buchanan County faces very low composite natural disaster risk (NRI Risk Index score 24.0, 24th national percentile), driven primarily by drought and hail exposure. Expected annual loss across all 18 hazard types is $13M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Buchanan County is very low, with a National Risk Index score of 24.0 out of 100 — placing it in the 24th 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.
Risk here concentrates in drought (extended dry periods that stress water supplies and agriculture) at Medium risk — $2M in expected annual loss and about 14.31 events per year; hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $1M in expected annual loss and about 4.74 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Low risk — $98K in expected annual loss and about 16.58 events per year. Across all hazards, FEMA estimates $13M in expected annual loss for a population of 21K.
Beyond physical exposure, Buchanan 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: Buchanan County has received 25 federal disaster declarations since 1965, including 11 for flood events and 11 for severe storm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 99 Iowa counties, Buchanan County ranks #78 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | Medium | 14.31 / yr | $2M |
| Hail | Medium | 4.74 / yr | $1M |
| Winter Weather | Low | 16.58 / yr | $98K |
| Strong Wind | Low | 5.30 / yr | $838K |
| Riverine Flood | Low | 2.11 / yr | $7M |
| Tornado | Low | 0.51 / yr | $1M |
| Cold Wave | Low | 8.05 / yr | $628K |
| Landslide | Very Low | 0.06 / yr | $312 |
| Heat Wave | Very Low | 4.89 / yr | $150K |
| Ice Storm | Very Low | 0.24 / yr | $37K |
| Earthquake | Very Low | 0.00 / yr | $32K |
| Lightning | Very Low | 40.91 / yr | $81K |
| Hurricane | Very Low | 0.01 / yr | $5K |
| Wildfire | Very Low | 0.00 / 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
Buchanan County has received 25 federal disaster declarations since 1965, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Flood (11), Severe Storm (11), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| 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 |
| August 2017 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| October 2016 | Flood | Severe Storms and Flooding |
| July 2014 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| July 2013 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| July 2013 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| July 2010 | Severe Storm | Severe Storms, Flooding, and Tornadoes |
Showing the 10 most recent of 25 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Buchanan County?
Buchanan County has a composite FEMA National Risk Index score of 24.0 out of 100, placing it in the Very Low category and the 24th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Buchanan County?
The three highest-rated hazards are Drought (Medium, $2M EAL), Hail (Medium, $1M EAL), Winter Weather (Low, $98K EAL). These account for most of the county's expected annual losses.
How does Buchanan County compare to other Iowa counties?
Buchanan County ranks #78 of 99 Iowa counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Buchanan County had?
FEMA records 25 federal disaster declarations for Buchanan County since 1965, most often 11 for flood events and 11 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. Buchanan County's $13M EAL is a statistical average, not a guarantee for any specific year or address.