Iosco County, Michigan Natural Disaster Risk
FEMA National Risk Index assessment · MI
Very LowComposite Risk Score
National percentile: 38th
Iosco County faces very low composite natural disaster risk (NRI Risk Index score 37.8, 38th national percentile), driven primarily by winter weather and cold wave exposure. Expected annual loss across all 18 hazard types is $8M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Iosco County is very low, with a National Risk Index score of 37.8 out of 100 — placing it in the 38th 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 winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $183K in expected annual loss and about 12.95 events per year; cold wave (prolonged spells of dangerously low temperatures) at Medium risk — $1M in expected annual loss and about 2.16 events per year; and lightning (electrical discharges from storms that ignite fires and cause casualties) at Medium risk — $298K in expected annual loss and about 26.52 events per year. Across all hazards, FEMA estimates $8M in expected annual loss for a population of 25K.
Beyond physical exposure, Iosco County has a very high social vulnerability rating (how susceptible the population is to harm) and a high community resilience rating (its capacity to prepare for and recover from disasters). Higher vulnerability is partly offset by strong community resilience and recovery capacity.
The county's disaster history tells the same story: Iosco County has received 11 federal disaster declarations since 1972, including 4 for flood events and 2 for biological events. The most recent was Severe Storms, Tornadoes, and Flooding (flood), declared in June 2026.
Among 83 Michigan counties, Iosco County ranks #53 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Winter Weather | Medium | 12.95 / yr | $183K |
| Cold Wave | Medium | 2.16 / yr | $1M |
| Lightning | Medium | 26.52 / yr | $298K |
| Wildfire | Very Low | 0.00 / yr | $62K |
| Hail | Low | 1.30 / yr | $221K |
| Riverine Flood | Low | 0.18 / yr | $5M |
| Strong Wind | Medium | 1.49 / yr | $415K |
| Coastal Flood | Very Low | 0.01 / yr | $16K |
| Hurricane | Very Low | 0.01 / yr | $20K |
| Tornado | Low | 0.23 / yr | $521K |
| Landslide | Very Low | 0.09 / yr | $254 |
| Ice Storm | Very Low | 0.18 / yr | $18K |
| Earthquake | Very Low | 0.00 / yr | $27K |
| Heat Wave | Very Low | 1.00 / yr | $43K |
| Avalanche | 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
Iosco County has received 11 federal disaster declarations since 1972, most recently Severe Storms, Tornadoes, and Flooding in June 2026. Most frequent causes: Flood (4), Biological (2), Snowstorm (2).
| Declared | Type | Disaster |
|---|---|---|
| June 2026 | Flood | Severe Storms, Tornadoes, and Flooding |
| July 2020 | Dam/Levee Break | Severe Storms and Flooding |
| 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 |
| September 1985 | Flood | Severe Storms and Flooding |
| January 1978 | Snowstorm | Blizzards & Snowstorms |
| March 1977 | Drought | Drought |
| April 1973 | Flood | Severe Storms & Flooding |
Showing the 10 most recent of 11 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Iosco County?
Iosco County has a composite FEMA National Risk Index score of 37.8 out of 100, placing it in the Very Low category and the 38th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Iosco County?
The three highest-rated hazards are Winter Weather (Medium, $183K EAL), Cold Wave (Medium, $1M EAL), Lightning (Medium, $298K EAL). These account for most of the county's expected annual losses.
How does Iosco County compare to other Michigan counties?
Iosco County ranks #53 of 83 Michigan counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Iosco County had?
FEMA records 11 federal disaster declarations for Iosco County since 1972, most often 4 for flood events and 2 for biological events. The most recent was Severe Storms, Tornadoes, and Flooding, 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. Iosco County's $8M EAL is a statistical average, not a guarantee for any specific year or address.