McCook County, South Dakota Natural Disaster Risk
FEMA National Risk Index assessment · SD
LowComposite Risk Score
National percentile: 43th
McCook County faces low composite natural disaster risk (NRI Risk Index score 43.4, 43th national percentile), driven primarily by winter weather and drought exposure. Expected annual loss across all 18 hazard types is $21M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates McCook County at low composite risk, with a National Risk Index score of 43.4 out of 100 — placing it in the 43rd 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 winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $358K in expected annual loss and about 16.58 events per year; drought (extended dry periods that stress water supplies and agriculture) at Medium risk — $1M in expected annual loss and about 12.91 events per year; and hail (ice stones from severe thunderstorms that damage property and crops) at Low risk — $918K in expected annual loss and about 5.87 events per year. Across all hazards, FEMA estimates $21M in expected annual loss for a population of 6K.
Beyond physical exposure, McCook 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: McCook County has received 21 federal disaster declarations since 1976, including 9 for severe storm events and 7 for flood events. The most recent was Severe Storms, Straight-Line Winds, and Flooding (flood), declared in August 2024.
Among 66 South Dakota counties, McCook County ranks #16 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Winter Weather | Medium | 16.58 / yr | $358K |
| Drought | Medium | 12.91 / yr | $1M |
| Hail | Low | 5.87 / yr | $918K |
| Ice Storm | Medium | 0.70 / yr | $325K |
| Tornado | Medium | 0.42 / yr | $4M |
| Wildfire | Very Low | 0.00 / yr | $154K |
| Riverine Flood | Low | 0.79 / yr | $13M |
| Cold Wave | Low | 8.11 / yr | $969K |
| Landslide | Very Low | 0.07 / yr | $395 |
| Strong Wind | Low | 3.80 / yr | $412K |
| Earthquake | Very Low | 0.00 / yr | $44K |
| Heat Wave | Very Low | 5.53 / yr | $91K |
| Lightning | Very Low | 36.83 / yr | $26K |
| 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
McCook County has received 21 federal disaster declarations since 1976, most recently Severe Storms, Straight-Line Winds, and Flooding in August 2024. Most frequent causes: Severe Storm (9), Flood (7), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| August 2024 | Flood | Severe Storms, Straight-Line Winds, and Flooding |
| June 2022 | Severe Storm | Severe Storm, Straight-Line Winds, Tornadoes, and Flooding |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| November 2019 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| June 2019 | Flood | Severe Winter Storm, Snowstorm, and Flooding |
| July 2015 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| May 2013 | Severe Storm | Severe Winter Storm and Snowstorm |
| May 2010 | Flood | Flooding |
| March 2010 | Severe Storm | Severe Winter Storm |
Showing the 10 most recent of 21 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for McCook County?
McCook County has a composite FEMA National Risk Index score of 43.4 out of 100, placing it in the Low category and the 43th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in McCook County?
The three highest-rated hazards are Winter Weather (Medium, $358K EAL), Drought (Medium, $1M EAL), Hail (Low, $918K EAL). These account for most of the county's expected annual losses.
How does McCook County compare to other South Dakota counties?
McCook County ranks #16 of 66 South Dakota counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has McCook County had?
FEMA records 21 federal disaster declarations for McCook County since 1976, most often 9 for severe storm events and 7 for flood events. The most recent was Severe Storms, Straight-Line Winds, and Flooding, declared in August 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. McCook County's $21M EAL is a statistical average, not a guarantee for any specific year or address.