Ontonagon County, Michigan: Natural Disaster Risk and History
Ontonagon County, Michigan has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 4.2 out of 100, higher than about 4% of US counties, with winter storms, cold waves and wildfires scoring highest of its 18 hazards and $2.4 million a year in expected losses.
OpenFEMA lists 6 federal disaster declarations that included Ontonagon County since 1977, not counting 2 for COVID-19; the latest is DR-4121-MI (Flooding, declared 18 June 2013). NOAA's Storm Prediction Center recorded 3 tornadoes touching Ontonagon County from 1950 to 2025.
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Population 5,803 Buildings worth $1.9 billion Area 3,778 sq mi Risk rank in Michigan 81 of 83 FIPS 26131
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Winter weather | Relatively Low | 57.8 | $69,965 | about 39 a year | 738 |
| Cold wave | Relatively Low | 46.2 | $675,635 | about 4.1 a year | 78 |
| Wildfire | Very Low | 31.6 | $12,987 | rarer than once in 1,000 years | — |
| Lightning | Relatively Low | 26.6 | $78,850 | about 24 a year | 29,576 strikes |
| Drought | Very Low | 22.4 | $5,668 | about 2.9 a year | 77 |
| Strong wind | Very Low | 16.7 | $118,345 | about once every 1.2 years | 12 |
| Hail | Very Low | 15.9 | $45,333 | about once every 1.3 years | 29 |
| Coastal flooding | Very Low | 15.0 | — | rarer than once in 1,000 years | — |
| Inland flooding | Very Low | 13.0 | $1.3 million | about once every 3.5 years | 8 |
| Landslide | Very Low | 8.5 | $16 | about once every 3.0 years | — |
| Tornado | Very Low | 7.5 | $32,295 | about once every 6.8 years | 2 |
| Heat wave | Very Low | 5.9 | $6,040 | about once every 3.2 years | 6 |
| Ice storm | Very Low | 2.2 | $717 | about once every 67 years | 0 |
| Earthquake | No Rating | 0.0 | — | rarer than once in 1,000 years | — |
| Hurricane | No Rating | 0.0 | — | rarer than once in 1,000 years | 0 |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Insufficient Data | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 6
Most common: Flood 2, Hurricane 1, Freezing 1, Snowstorm 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 2 | Snowstorm, Drought |
| 1990s | 1 | Freezing |
| 2000s | 2 | Hurricane, Flood |
| 2010s | 1 | Flood |
The last 6
Widest declarations that included Ontonagon County
- Hurricane Katrina Evacuation (2005, EM-3225-MI): 83 Michigan counties designated.
- Blizzards & Snowstorms (1978, EM-3057-MI): 83 Michigan counties designated.
- Drought (1977, EM-3035-MI): 44 Michigan counties designated.
Named storms in its declarations: Hurricane Katrina (2005).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Michigan also had 3 statewide declarations with no county list.
Tornado record since 1950 3
| Tornadoes touching the county | 3 |
|---|---|
| Strongest-rated | (E)F1 ×1 |
| Peak month | May (1) |
| Deadliest | — |
| Longest path | 30 Jun 1953, F1, 10.9 mi path |
| Most recent | 19 Aug 2011, EF0, 1.5 mi path |
| Deaths / injuries on those paths | 0 / 0 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 2 | 1 | 0 | 0 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 0 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Ontonagon County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Ontonagon County (this page) | — | Very Low | 4.2 | Winter weather |
| Gogebic County | 41 km | Very Low | 25.6 | Lightning |
| Houghton County | 54 km | Very Low | 24.3 | Winter weather |
| Vilas County, WI | 70 km | Relatively Low | 63.3 | Cold wave |
| Baraga County | 72 km | Very Low | 10.7 | Cold wave |
| Iron County | 79 km | Relatively Low | 55.1 | Cold wave |
Nearest by distance between county centres. Every county in Michigan, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively High 66.2 |
|---|---|
| Community resilience | Relatively High 67.7 |
| Community risk factor | 1.26 |
| Expected annual loss, all hazards | $2.4 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Ontonagon County's main hazards
- Right now: National Weather Service alerts for Michigan · all official warnings on Global Incident Tracker.
- Winter weather: Power outages now · Carbon monoxide in winter
- Cold wave: Carbon monoxide in winter · Power outages now
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Ontonagon County
What natural disasters is Ontonagon County, Michigan most at risk from?
Ontonagon County, Michigan has a Very Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 4.2 out of 100, higher than about 4% of US counties, with winter storms, cold waves and wildfires scoring highest of its 18 hazards and $2.4 million a year in expected losses.
How many federal disaster declarations has Ontonagon County had?
OpenFEMA lists 6 federal disaster declarations that included Ontonagon County since 1977, not counting 2 for COVID-19; the latest is DR-4121-MI (Flooding, declared 18 June 2013). Another 3 Michigan declarations were made statewide without a county list.
How many tornadoes have hit Ontonagon County?
NOAA's Storm Prediction Center recorded 3 tornadoes touching Ontonagon County from 1950 to 2025.
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.