Delta County, Michigan: Natural Disaster Risk and History
Delta County, Michigan has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 53.1 out of 100, higher than about 53% of US counties, with cold waves, hail and lightning scoring highest of its 18 hazards and $15 million a year in expected losses.
OpenFEMA lists 4 federal disaster declarations that included Delta County since 1977, not counting 2 for COVID-19; the latest is EM-3225-MI (Hurricane Katrina Evacuation, declared 7 September 2005). NOAA's Storm Prediction Center recorded 12 tornadoes touching Delta County from 1950 to 2025.
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Population 36,797 Buildings worth $10 billion Area 2,011 sq mi Risk rank in Michigan 41 of 83 FIPS 26041
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Cold wave | Relatively Moderate | 87.8 | $5.0 million | about 3.6 a year | 69 |
| Hail | Relatively Moderate | 83.2 | $885,462 | about once every 1.1 years | 43 |
| Lightning | Relatively Moderate | 64.4 | $339,135 | about 25 a year | 51,837 strikes |
| Inland flooding | Relatively Low | 60.4 | $7.7 million | about once every 2.3 years | 12 |
| Landslide | Very Low | 51.9 | $1,285 | about once every 4.8 years | — |
| Wildfire | Very Low | 49.7 | $39,135 | rarer than once in 1,000 years | — |
| Strong wind | Relatively Low | 39.1 | $340,494 | about once every 1.1 years | 26 |
| Coastal flooding | Very Low | 36.6 | $8,030 | about once every 76 years | — |
| Winter weather | Relatively Low | 27.2 | $21,832 | about 19 a year | 355 |
| Tornado | Very Low | 24.2 | $288,288 | about once every 7.2 years | 9 |
| Drought | Very Low | 21.5 | $4,873 | about 1.5 a year | 49 |
| Ice storm | Very Low | 16.1 | $9,139 | about once every 38 years | 2 |
| Heat wave | Very Low | 12.8 | $23,850 | about once every 4.7 years | 4 |
| Earthquake | Very Low | 6.7 | $5,425 | rarer than once in 1,000 years | — |
| Hurricane | No Rating | 0.0 | — | — | 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 4
Most common: Hurricane 1, Freezing 1, Snowstorm 1, Drought 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 2 | Snowstorm, Drought |
| 1990s | 1 | Freezing |
| 2000s | 1 | Hurricane |
The last 4
Widest declarations that included Delta 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 12
| Tornadoes touching the county | 12 |
|---|---|
| Strongest-rated | (E)F3 ×1 |
| Peak month | July (7) |
| Deadliest | 19 Jul 1992, F2, 0.2 mi path, 0 killed, 2 injured |
| Longest path | 11 Jul 1987, F3, 71 mi path |
| Most recent | 31 Aug 2020, EF1, 0.6 mi path |
| Deaths / injuries on those paths | 0 / 3 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 4 | 5 | 2 | 1 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 0 | 1 | 3 | 1 | 4 | 2 | 0 | 1 |
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 Delta County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Delta County (this page) | — | Relatively Low | 53.1 | Cold wave |
| Alger County | 60 km | Very Low | 9.6 | Lightning |
| Menominee County | 62 km | Relatively Low | 44.4 | Cold wave |
| Schoolcraft County | 64 km | Very Low | 6.7 | Lightning |
| Dickinson County | 74 km | Relatively Low | 59.3 | Cold wave |
| Marquette County | 79 km | Relatively Low | 69.8 | Hail |
Nearest by distance between county centres. Every county in Michigan, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively High 65.5 |
|---|---|
| Community resilience | Very High 90.9 |
| Community risk factor | 1.24 |
| Expected annual loss, all hazards | $15 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 Delta County's main hazards
- Right now: National Weather Service alerts for Michigan · all official warnings on Global Incident Tracker.
- Cold wave: Carbon monoxide in winter · Power outages now
- Hail: Weather alerts for Michigan
- Lightning: Weather alerts for Michigan
- 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 Delta County
What natural disasters is Delta County, Michigan most at risk from?
Delta County, Michigan has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 53.1 out of 100, higher than about 53% of US counties, with cold waves, hail and lightning scoring highest of its 18 hazards and $15 million a year in expected losses.
How many federal disaster declarations has Delta County had?
OpenFEMA lists 4 federal disaster declarations that included Delta County since 1977, not counting 2 for COVID-19; the latest is EM-3225-MI (Hurricane Katrina Evacuation, declared 7 September 2005). Another 3 Michigan declarations were made statewide without a county list.
How many tornadoes have hit Delta County?
NOAA's Storm Prediction Center recorded 12 tornadoes touching Delta County from 1950 to 2025. The deadliest: 19 Jul 1992, F2, 0.2 mi path, 0 killed, 2 injured (deaths and injuries are for the whole path).
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.