Washtenaw County, MI
FEMA National Risk Index scores, disaster declarations & hazard data
Washtenaw County has experienced 12 federally declared disasters since 1965, most recently Severe Storms, Tornadoes, And Flooding in 2026. Its overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Washtenaw County's highest-rated hazards are strong wind, tornado, and cold wave, with its top risk rated "Relatively High" by FEMA's National Risk Index. NOAA records 56 storm events in the county over the past decade.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Washtenaw County has been designated in 12 declarations since 1965, covering 7 disaster types including snowstorm (3), flood (2), severe storm (2).
| Year | Type | Event name |
|---|---|---|
| 2026 | Flood | Severe Storms, Tornadoes, And Flooding |
| 2021 | Severe Storm | Severe Storms, Flooding, And Tornadoes |
| 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 |
| 1999 | Snowstorm | Mi - Severe Weather 1/2 /99 |
| 1980 | Flood | Severe Storms & Flooding |
Showing the 10 most recent of 12 total declarations since 1965.
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 | 43.8 | 0 | 0 | — |
| Inland Flooding | Relatively Moderate | 90.3 | 7 | 0 | $7.5M |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Relatively Low | 74.3 | — | — | — |
| Heat Wave | Relatively Moderate | 87.4 | 2 | 0 | — |
| Tornado | Relatively High | 96.9 | 0 | 0 | — |
| Hurricane | Very Low | 48.3 | 0 | 0 | — |
| Hail | Relatively Moderate | 85.8 | 48 | 0 | $1.0M |
| Strong Wind | Relatively High | 98 | 0 | 0 | — |
| Winter Weather | Relatively Moderate | 73 | 0 | 0 | — |
| Ice Storm | Relatively High | 90.4 | — | — | — |
| Cold Wave | Relatively High | 93.1 | — | — | — |
| Lightning | Relatively High | 88.8 | 0 | 0 | — |
| Drought | No Rating | 0 | 0 | 0 | — |
| Landslide | Relatively Low | 69.9 | 0 | 0 | — |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| 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
Washtenaw County ranks in the 32nd 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 | 32nd | Low |
| Socioeconomic status | 26th | Low |
| Household characteristics | 2nd | Very low |
| Racial & ethnic minority status | 68th | Moderate |
| Housing type & transportation | 81st | High |
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 | 12th | Very Low |
| Risk to homes | 11th | Very Low |
| Buildings in direct exposure zone | 38.5% | — |
NOAA tracked 56 weather events in this county over 2016–2025: 29 in 2016–20 vs 27 in 2021–25 (-7% — relatively stable).
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 Washtenaw County?
According to the FEMA National Risk Index, the highest-risk hazards in Washtenaw County, Michigan are strong wind, tornado, and cold wave. The county's overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Has Washtenaw County received federal disaster declarations?
Yes. Washtenaw County has received 12 federal disaster declarations since 1965, including declarations in 2026. The most common disaster type on record is snowstorm (3 declarations).
Has Washtenaw County had any FEMA disaster declarations in 2024, 2025, or 2026?
Yes. Recent federal disaster declarations for Washtenaw County include Severe Storms, Tornadoes, And Flooding (2026). See the declarations table above for the full history since 1965.
How does Washtenaw 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 Lenawee County, MI has the lowest (Relatively Low). Washtenaw County is rated Relatively Moderate overall.
How is Washtenaw County's composite disaster risk index calculated?
Washtenaw 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. Washtenaw County's composite score of 89 means its overall natural hazard risk is higher than 89% of US counties.