Sioux County, Nebraska Natural Disaster Risk
FEMA National Risk Index assessment · NE
Very LowComposite Risk Score
National percentile: 1th
Sioux County faces very low composite natural disaster risk (NRI Risk Index score 1.4, 1th national percentile), driven primarily by drought and wildfire exposure. Expected annual loss across all 18 hazard types is $2M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Sioux County at very low composite risk, with a National Risk Index score of 1.4 out of 100 — placing it in the 1st 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 — $670K in expected annual loss and about 96.44 events per year; wildfire (uncontrolled fires that spread across wildland and into communities) at Low risk — $216K in expected annual loss and about 0.00 events per year; and hail (ice stones from severe thunderstorms that damage property and crops) at Very Low risk — $163K in expected annual loss and about 4.25 events per year. Across all hazards, FEMA estimates $2M in expected annual loss for a population of 1K.
Beyond physical exposure, Sioux County has a very low 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). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
History supports the rating: Sioux County has received 14 federal disaster declarations since 1991, including 6 for severe storm events and 3 for fire events. The most recent was South Fork Fire (fire), declared in June 2026.
Among 93 Nebraska counties, Sioux County ranks #81 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | Medium | 96.44 / yr | $670K |
| Wildfire | Low | 0.00 / yr | $216K |
| Hail | Very Low | 4.25 / yr | $163K |
| Winter Weather | Very Low | 16.69 / yr | $24K |
| Landslide | Very Low | 0.90 / yr | $171 |
| Cold Wave | Very Low | 5.62 / yr | $282K |
| Tornado | Very Low | 0.86 / yr | $107K |
| Earthquake | Very Low | 0.00 / yr | $11K |
| Ice Storm | Very Low | 0.02 / yr | $3K |
| Lightning | Very Low | 44.59 / yr | $17K |
| Heat Wave | Very Low | 0.74 / yr | $3K |
| Strong Wind | Very Low | 1.18 / yr | $20K |
| Riverine Flood | Very Low | 0.21 / yr | $423K |
| 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
Sioux County has received 14 federal disaster declarations since 1991, most recently South Fork Fire in June 2026. Most frequent causes: Severe Storm (6), Fire (3), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| June 2026 | Fire | South Fork Fire |
| May 2024 | Severe Storm | Severe Winter Storm and Straight-Line Winds |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| March 2019 | Flood | Severe Winter Storm, Straight-Line Winds, and Flooding |
| August 2017 | Severe Storm | Severe Storms, Tornadoes, and Straight-Line Winds |
| June 2015 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| November 2013 | Severe Storm | Severe Storms, Winter Storms, Tornadoes and Flooding |
| August 2012 | Fire | Region 23 Fire Complex |
| July 2010 | Severe Storm | Severe Storms and Flooding |
Showing the 10 most recent of 14 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Sioux County?
Sioux County has a composite FEMA National Risk Index score of 1.4 out of 100, placing it in the Very Low category and the 1th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Sioux County?
The three highest-rated hazards are Drought (Medium, $670K EAL), Wildfire (Low, $216K EAL), Hail (Very Low, $163K EAL). These account for most of the county's expected annual losses.
How does Sioux County compare to other Nebraska counties?
Sioux County ranks #81 of 93 Nebraska counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Sioux County had?
FEMA records 14 federal disaster declarations for Sioux County since 1991, most often 6 for severe storm events and 3 for fire events. The most recent was South Fork Fire, declared in June 2026.
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. Sioux County's $2M EAL is a statistical average, not a guarantee for any specific year or address.