Shiawassee County, Michigan Natural Disaster Risk
FEMA National Risk Index assessment · MI
LowComposite Risk Score
National percentile: 62th
Shiawassee County faces low composite natural disaster risk (NRI Risk Index score 62.2, 62th national percentile), driven primarily by strong wind and tornado exposure. Expected annual loss across all 18 hazard types is $22M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Shiawassee County at low composite risk, with a National Risk Index score of 62.2 out of 100 — placing it in the 62nd 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 strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at High risk — $3M in expected annual loss and about 5.67 events per year; tornado (violently rotating columns of air capable of catastrophic local damage) at Medium risk — $5M in expected annual loss and about 0.25 events per year; and cold wave (prolonged spells of dangerously low temperatures) at Medium risk — $5M in expected annual loss and about 2.79 events per year. Across all hazards, FEMA estimates $22M in expected annual loss for a population of 68K.
Beyond physical exposure, Shiawassee County has a medium 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: Shiawassee County has received 14 federal disaster declarations since 1965, including 4 for flood events and 3 for severe storm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 83 Michigan counties, Shiawassee County ranks #30 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Strong Wind | High | 5.67 / yr | $3M |
| Tornado | Medium | 0.25 / yr | $5M |
| Cold Wave | Medium | 2.79 / yr | $5M |
| Ice Storm | Medium | 1.50 / yr | $193K |
| Hail | Low | 2.87 / yr | $427K |
| Heat Wave | Low | 2.47 / yr | $475K |
| Riverine Flood | Low | 0.50 / yr | $8M |
| Landslide | Very Low | 0.08 / yr | $775 |
| Hurricane | Very Low | 0.02 / yr | $28K |
| Earthquake | Very Low | 0.00 / yr | $144K |
| Lightning | Low | 33.56 / yr | $114K |
| Winter Weather | Very Low | 11.32 / yr | $19K |
| Wildfire | Very Low | 0.00 / yr | $3K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Drought | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Shiawassee County has received 14 federal disaster declarations since 1965, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Flood (4), Severe Storm (3), Snowstorm (3).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| June 2004 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| January 2001 | Snowstorm | Snow |
| June 1998 | Severe Storm | Severe Storms |
| September 1986 | Flood | Severe Storms & Flooding |
| September 1985 | Flood | Severe Storms and Flooding |
| January 1978 | Snowstorm | Blizzards & Snowstorms |
| February 1977 | Snowstorm | Snowstorms |
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 Shiawassee County?
Shiawassee County has a composite FEMA National Risk Index score of 62.2 out of 100, placing it in the Low category and the 62th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Shiawassee County?
The three highest-rated hazards are Strong Wind (High, $3M EAL), Tornado (Medium, $5M EAL), Cold Wave (Medium, $5M EAL). These account for most of the county's expected annual losses.
How does Shiawassee County compare to other Michigan counties?
Shiawassee County ranks #30 of 83 Michigan counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Shiawassee County had?
FEMA records 14 federal disaster declarations for Shiawassee County since 1965, most often 4 for flood events and 3 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. Shiawassee County's $22M EAL is a statistical average, not a guarantee for any specific year or address.