Black Hawk County, Iowa Natural Disaster Risk
FEMA National Risk Index assessment · IA
LowComposite Risk Score
National percentile: 77th
Black Hawk County faces low composite natural disaster risk (NRI Risk Index score 76.6, 77th national percentile), driven primarily by drought and strong wind exposure. Expected annual loss across all 18 hazard types is $42M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Black Hawk County is low, with a National Risk Index score of 76.6 out of 100 — placing it in the 77th national percentile and below the national average for natural-disaster risk. 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 High risk — $4M in expected annual loss and about 16.18 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at High risk — $3M in expected annual loss and about 5.35 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at High risk — $598K in expected annual loss and about 17.79 events per year. Across all hazards, FEMA estimates $42M in expected annual loss for a population of 131K.
Beyond physical exposure, Black Hawk 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.
The federal record bears this out: Black Hawk County has received 20 federal disaster declarations since 1965, including 9 for flood events and 8 for severe storm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 99 Iowa counties, Black Hawk County ranks #7 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | High | 16.18 / yr | $4M |
| Strong Wind | High | 5.35 / yr | $3M |
| Winter Weather | High | 17.79 / yr | $598K |
| Tornado | High | 0.54 / yr | $9M |
| Hail | Medium | 5.03 / yr | $2M |
| Riverine Flood | Medium | 4.50 / yr | $20M |
| Ice Storm | Medium | 0.31 / yr | $232K |
| Cold Wave | Medium | 8.68 / yr | $2M |
| Lightning | Low | 41.59 / yr | $319K |
| Heat Wave | Low | 3.95 / yr | $330K |
| Earthquake | Very Low | 0.00 / yr | $167K |
| Wildfire | Very Low | 0.00 / yr | $25K |
| Landslide | Very Low | 0.06 / yr | $409 |
| Hurricane | Very Low | 0.01 / yr | $5K |
| 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
Black Hawk County has received 20 federal disaster declarations since 1965, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Flood (9), Severe Storm (8), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| October 2016 | Flood | Severe Storms and Flooding |
| August 2014 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| July 2010 | Severe Storm | Severe Storms, Flooding, and Tornadoes |
| August 2009 | Severe Storm | Severe Storm |
| May 2008 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| March 2007 | Severe Storm | Severe Winter Storms |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| May 2004 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
Showing the 10 most recent of 20 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Black Hawk County?
Black Hawk County has a composite FEMA National Risk Index score of 76.6 out of 100, placing it in the Low category and the 77th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Black Hawk County?
The three highest-rated hazards are Drought (High, $4M EAL), Strong Wind (High, $3M EAL), Winter Weather (High, $598K EAL). These account for most of the county's expected annual losses.
How does Black Hawk County compare to other Iowa counties?
Black Hawk County ranks #7 of 99 Iowa counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Black Hawk County had?
FEMA records 20 federal disaster declarations for Black Hawk County since 1965, most often 9 for flood events and 8 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. Black Hawk County's $42M EAL is a statistical average, not a guarantee for any specific year or address.