Adams County, Iowa Natural Disaster Risk
FEMA National Risk Index assessment · IA
Very LowComposite Risk Score
National percentile: 20th
Adams County faces very low composite natural disaster risk (NRI Risk Index score 20.4, 20th national percentile), driven primarily by drought and landslide exposure. Expected annual loss across all 18 hazard types is $8M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Adams County at very low composite risk, with a National Risk Index score of 20.4 out of 100 — placing it in the 20th 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.
Most of Adams County's expected losses come from drought (extended dry periods that stress water supplies and agriculture) at High risk — $3M in expected annual loss and about 6.15 events per year; landslide (downhill movement of rock, soil, and debris on unstable slopes) at Very Low risk — $2K in expected annual loss and about 0.18 events per year; and cold wave (prolonged spells of dangerously low temperatures) at Low risk — $1M in expected annual loss and about 4.63 events per year. Across all hazards, FEMA estimates $8M in expected annual loss for a population of 4K.
Beyond physical exposure, Adams County has a low social vulnerability rating (how susceptible the population is to harm) and a medium community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
The county's disaster history tells the same story: Adams County has received 17 federal disaster declarations since 1972, including 7 for severe storm events and 5 for flood events. The most recent was Severe Storms, Tornadoes, and Flooding (severe storm), declared in May 2024.
Among 99 Iowa counties, Adams County ranks #85 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | High | 6.15 / yr | $3M |
| Landslide | Very Low | 0.18 / yr | $2K |
| Cold Wave | Low | 4.63 / yr | $1M |
| Heat Wave | Low | 7.63 / yr | $468K |
| Hail | Low | 5.97 / yr | $286K |
| Tornado | Low | 0.34 / yr | $848K |
| Wildfire | Very Low | 0.00 / yr | $17K |
| Strong Wind | Low | 4.58 / yr | $292K |
| Winter Weather | Very Low | 11.47 / yr | $18K |
| Ice Storm | Very Low | 0.55 / yr | $16K |
| Riverine Flood | Very Low | 0.96 / yr | $2M |
| Hurricane | Very Low | 0.01 / yr | $1K |
| Earthquake | Very Low | 0.00 / yr | $9K |
| Lightning | Very Low | 45.20 / yr | $18K |
| 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
Adams County has received 17 federal disaster declarations since 1972, most recently Severe Storms, Tornadoes, and Flooding in May 2024. Most frequent causes: Severe Storm (7), Flood (5), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| May 2024 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| March 2019 | Flood | Severe Storms and Flooding |
| July 2014 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| July 2010 | Severe Storm | Severe Storms, Flooding, and Tornadoes |
| March 2010 | Severe Storm | Severe Winter Storm |
| May 2008 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| January 2008 | Severe Ice Storm | Severe Winter Storm |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
Showing the 10 most recent of 17 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Adams County?
Adams County has a composite FEMA National Risk Index score of 20.4 out of 100, placing it in the Very Low category and the 20th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Adams County?
The three highest-rated hazards are Drought (High, $3M EAL), Landslide (Very Low, $2K EAL), Cold Wave (Low, $1M EAL). These account for most of the county's expected annual losses.
How does Adams County compare to other Iowa counties?
Adams County ranks #85 of 99 Iowa counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Adams County had?
FEMA records 17 federal disaster declarations for Adams County since 1972, most often 7 for severe storm events and 5 for flood events. The most recent was Severe Storms, Tornadoes, and Flooding, declared in May 2024.
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. Adams County's $8M EAL is a statistical average, not a guarantee for any specific year or address.