Ontonagon County, Michigan Natural Disaster Risk
FEMA National Risk Index assessment · MI
Very LowComposite Risk Score
National percentile: 4th
Ontonagon County faces very low composite natural disaster risk (NRI Risk Index score 4.2, 4th national percentile), driven primarily by winter weather and cold wave 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 Ontonagon County at very low composite risk, with a National Risk Index score of 4.2 out of 100 — placing it in the 4th 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.
Most of Ontonagon County's expected losses come from winter weather (heavy snow, blizzards, and hazardous winter conditions) at Low risk — $70K in expected annual loss and about 38.84 events per year; cold wave (prolonged spells of dangerously low temperatures) at Low risk — $676K in expected annual loss and about 4.11 events per year; and wildfire (uncontrolled fires that spread across wildland and into communities) at Very Low risk — $13K in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $2M in expected annual loss for a population of 6K.
Beyond physical exposure, Ontonagon County has a 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: Ontonagon County has received 8 federal disaster declarations since 1977, including 2 for biological events and 2 for flood events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 83 Michigan counties, Ontonagon County ranks #81 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Winter Weather | Low | 38.84 / yr | $70K |
| Cold Wave | Low | 4.11 / yr | $676K |
| Wildfire | Very Low | 0.00 / yr | $13K |
| Lightning | Low | 23.83 / yr | $79K |
| Drought | Very Low | 2.88 / yr | $6K |
| Strong Wind | Very Low | 0.82 / yr | $118K |
| Hail | Very Low | 0.74 / yr | $45K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Riverine Flood | Very Low | 0.29 / yr | $1M |
| Landslide | Very Low | 0.33 / yr | $16 |
| Tornado | Very Low | 0.15 / yr | $32K |
| Heat Wave | Very Low | 0.32 / yr | $6K |
| Ice Storm | Very Low | 0.01 / yr | $717 |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Earthquake | 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
Ontonagon County has received 8 federal disaster declarations since 1977, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Biological (2), Flood (2), Hurricane (1).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2013 | Flood | Flooding |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| May 2002 | Flood | Flooding |
| May 1994 | Freezing | Severe Deep Freeze |
| January 1978 | Snowstorm | Blizzards & Snowstorms |
| March 1977 | Drought | Drought |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Ontonagon County?
Ontonagon County has a composite FEMA National Risk Index score of 4.2 out of 100, placing it in the Very Low category and the 4th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Ontonagon County?
The three highest-rated hazards are Winter Weather (Low, $70K EAL), Cold Wave (Low, $676K EAL), Wildfire (Very Low, $13K EAL). These account for most of the county's expected annual losses.
How does Ontonagon County compare to other Michigan counties?
Ontonagon County ranks #81 of 83 Michigan counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Ontonagon County had?
FEMA records 8 federal disaster declarations for Ontonagon County since 1977, most often 2 for biological events and 2 for flood 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. Ontonagon County's $2M EAL is a statistical average, not a guarantee for any specific year or address.