Davis County, Iowa Natural Disaster Risk
FEMA National Risk Index assessment · IA
LowComposite Risk Score
National percentile: 50th
Davis County faces low composite natural disaster risk (NRI Risk Index score 50.3, 50th national percentile), driven primarily by drought and landslide exposure. Expected annual loss across all 18 hazard types is $11M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Davis County at low composite risk, with a National Risk Index score of 50.3 out of 100 — placing it in the 50th 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.
Most of Davis County's expected losses come from drought (extended dry periods that stress water supplies and agriculture) at High risk — $5M in expected annual loss and about 14.41 events per year; landslide (downhill movement of rock, soil, and debris on unstable slopes) at Low risk — $10K in expected annual loss and about 0.27 events per year; and heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at Low risk — $827K in expected annual loss and about 7.58 events per year. Across all hazards, FEMA estimates $11M in expected annual loss for a population of 9K.
Beyond physical exposure, Davis County has a very high social vulnerability rating (how susceptible the population is to harm) and a very low community resilience rating (its capacity to prepare for and recover from disasters). That combination — a more vulnerable population with limited resilience — can amplify the human cost of any given event.
The federal record bears this out: Davis County has received 17 federal disaster declarations since 1969, including 7 for severe storm events and 6 for flood events. The most recent was Severe Storms, Straight-Line Winds, and Tornadoes (severe storm), declared in February 2022.
Among 99 Iowa counties, Davis County ranks #25 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | High | 14.41 / yr | $5M |
| Landslide | Low | 0.27 / yr | $10K |
| Heat Wave | Low | 7.58 / yr | $827K |
| Tornado | Medium | 0.31 / yr | $2M |
| Wildfire | Low | 0.00 / yr | $110K |
| Strong Wind | Medium | 4.28 / yr | $560K |
| Lightning | Medium | 45.02 / yr | $213K |
| Hail | Low | 3.72 / yr | $240K |
| Cold Wave | Low | 4.58 / yr | $387K |
| Ice Storm | Low | 0.35 / yr | $30K |
| Earthquake | Very Low | 0.00 / yr | $68K |
| Riverine Flood | Very Low | 0.96 / yr | $3M |
| Winter Weather | Low | 11.11 / yr | $20K |
| 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
Davis County has received 17 federal disaster declarations since 1969, most recently Severe Storms, Straight-Line Winds, and Tornadoes in February 2022. Most frequent causes: Severe Storm (7), Flood (6), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| February 2022 | Severe Storm | Severe Storms, Straight-Line Winds, and Tornadoes |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| March 2019 | Flood | Severe Storms and Flooding |
| July 2015 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| July 2013 | Severe Storm | Severe Storms, Tornadoes, 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 |
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 Davis County?
Davis County has a composite FEMA National Risk Index score of 50.3 out of 100, placing it in the Low category and the 50th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Davis County?
The three highest-rated hazards are Drought (High, $5M EAL), Landslide (Low, $10K EAL), Heat Wave (Low, $827K EAL). These account for most of the county's expected annual losses.
How does Davis County compare to other Iowa counties?
Davis County ranks #25 of 99 Iowa counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Davis County had?
FEMA records 17 federal disaster declarations for Davis County since 1969, most often 7 for severe storm events and 6 for flood events. The most recent was Severe Storms, Straight-Line Winds, and Tornadoes, declared in February 2022.
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. Davis County's $11M EAL is a statistical average, not a guarantee for any specific year or address.