St. Clair County, MI
FEMA National Risk Index scores, disaster declarations & hazard data
St. Clair County has experienced 12 federally declared disasters since 1973, most recently Covid-19 in 2020. Its overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
St. Clair County's highest-rated hazards are cold wave, tornado, and ice storm, with its top risk rated "Relatively High" by FEMA's National Risk Index. Recorded storm events have decreased 75% over the past five years compared to the prior five-year period. Community vulnerability is relatively low (29th percentile nationally), indicating stronger recovery capacity than most US counties.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. St. Clair County has been designated in 12 declarations since 1973, covering 6 disaster types including severe storm (3), flood (3), biological (2).
| Year | Type | Event name |
|---|---|---|
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2005 | Hurricane | Hurricane Katrina Evacuation |
| 2004 | Severe Storm | Severe Storms, Tornadoes, And Flooding |
| 2003 | Other | Power Outage |
| 2001 | Snowstorm | Snow |
| 1996 | Severe Storm | Severe Storms And Flooding |
| 1978 | Snowstorm | Blizzards & Snowstorms |
| 1976 | Severe Storm | Severe Storms, Tornadoes, Icing & Flooding |
| 1975 | Flood | Severe Storms, High Winds & Flooding |
Showing the 10 most recent of 12 total declarations since 1973.
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Very Low | 33.5 | 0 | 0 | — |
| Inland Flooding | Relatively Moderate | 85.9 | 9 | 0 | $12.4M |
| Coastal Flooding | Relatively Low | 46.2 | 11 | 0 | $100K |
| Earthquake | Very Low | 50.8 | — | — | — |
| Heat Wave | Relatively Low | 63.8 | 2 | 0 | — |
| Tornado | Relatively Moderate | 87.2 | 1 | 0 | $40K |
| Hurricane | Very Low | 35.8 | 0 | 0 | — |
| Hail | Relatively Low | 48.1 | 12 | 0 | — |
| Strong Wind | Relatively High | 85.8 | 0 | 0 | — |
| Winter Weather | Relatively Low | 57.1 | 0 | 0 | — |
| Ice Storm | Relatively High | 86.4 | — | — | — |
| Cold Wave | Relatively High | 93.3 | — | — | — |
| Lightning | Relatively Low | 44 | 1 | 0 | — |
| Drought | No Rating | 0 | 0 | 0 | — |
| Landslide | Very Low | 37.6 | 0 | 0 | — |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Insufficient Data | — | — | — | — |
| Volcanic Activity | Not Applicable | — | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
St. Clair County ranks in the 29th percentile (Low) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 29th | Low |
| Socioeconomic status | 43rd | Low |
| Household characteristics | 37th | Low |
| Racial & ethnic minority status | 28th | Low |
| Housing type & transportation | 20th | Very low |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 6th | Very Low |
| Risk to homes | 6th | Very Low |
| Buildings in direct exposure zone | 52.9% | — |
NOAA tracked 35 weather events in this county over 2016–2025: 28 in 2016–20 vs 7 in 2021–25 (-75% — frequency decreasing).
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in St. Clair County?
According to the FEMA National Risk Index, the highest-risk hazards in St. Clair County, Michigan are cold wave, tornado, and ice storm. The county's overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Has St. Clair County received federal disaster declarations?
Yes. St. Clair County has received 12 federal disaster declarations since 1973, including declarations in 2020. The most common disaster type on record is severe storm (3 declarations).
Has St. Clair County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for St. Clair County since the start of 2024. Its most recent declaration on record is Covid-19 in 2020.
How does St. Clair County's natural hazard risk compare to nearby counties?
Among neighboring counties, Wayne County, MI has the highest overall natural hazard risk (Relatively High) and Lapeer County, MI has the lowest (Relatively Low). St. Clair County is rated Relatively Moderate overall.
How is St. Clair County's composite disaster risk index calculated?
St. Clair County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. St. Clair County's composite score of 82 means its overall natural hazard risk is higher than 82% of US counties.