Lenawee County, Michigan Natural Disaster Risk
FEMA National Risk Index assessment · MI
LowComposite Risk Score
National percentile: 70th
Lenawee County faces low composite natural disaster risk (NRI Risk Index score 69.9, 70th national percentile), driven primarily by strong wind and tornado exposure. Expected annual loss across all 18 hazard types is $30M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Lenawee County carries a low composite natural disaster risk, with a National Risk Index score of 69.9 out of 100 — placing it in the 70th 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 — $2M in expected annual loss and about 5.29 events per year; tornado (violently rotating columns of air capable of catastrophic local damage) at Medium risk — $5M in expected annual loss and about 0.38 events per year; and hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $1M in expected annual loss and about 3.23 events per year. Across all hazards, FEMA estimates $30M in expected annual loss for a population of 99K.
Beyond physical exposure, Lenawee County has a 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: Lenawee County has received 6 federal disaster declarations since 1965, including 2 for biological events and 2 for snowstorm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 83 Michigan counties, Lenawee County ranks #22 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Strong Wind | High | 5.29 / yr | $2M |
| Tornado | Medium | 0.38 / yr | $5M |
| Hail | Medium | 3.23 / yr | $1M |
| Cold Wave | Medium | 2.89 / yr | $5M |
| Ice Storm | Medium | 1.61 / yr | $343K |
| Riverine Flood | Low | 1.00 / yr | $15M |
| Lightning | Medium | 37.70 / yr | $545K |
| Earthquake | Low | 0.00 / yr | $550K |
| Winter Weather | Low | 8.95 / yr | $92K |
| Landslide | Very Low | 0.15 / yr | $2K |
| Heat Wave | Low | 3.58 / yr | $509K |
| Hurricane | Very Low | 0.01 / yr | $25K |
| Drought | Low | 0.49 / yr | $51K |
| Wildfire | Very Low | 0.00 / yr | $9K |
| 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
Lenawee County has received 6 federal disaster declarations since 1965, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Biological (2), Snowstorm (2), Hurricane (1).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| January 1999 | Snowstorm | Mi - Severe Weather 1/2 /99 |
| January 1978 | Snowstorm | Blizzards & Snowstorms |
| April 1965 | Tornado | Tornadoes & Severe Storms |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Lenawee County?
Lenawee County has a composite FEMA National Risk Index score of 69.9 out of 100, placing it in the Low category and the 70th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Lenawee County?
The three highest-rated hazards are Strong Wind (High, $2M EAL), Tornado (Medium, $5M EAL), Hail (Medium, $1M EAL). These account for most of the county's expected annual losses.
How does Lenawee County compare to other Michigan counties?
Lenawee County ranks #22 of 83 Michigan counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Lenawee County had?
FEMA records 6 federal disaster declarations for Lenawee County since 1965, most often 2 for biological events and 2 for snowstorm 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. Lenawee County's $30M EAL is a statistical average, not a guarantee for any specific year or address.