Photo: Flavinista · CC BY-SA 4.0FEMA expects less hazard damage per building in Ann Arbor than in 88% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Ann Arbor gets an A for hazard risk: lower expected damage per building than 88% of U.S. towns, #168 of 701 in Michigan. Most of that expected damage is river and rain flooding (66%), then tornadoes (20%). Flood insurance has paid 34 claims here since 1980.
Graded on FEMA’s expected yearly building damage per dollar of building value (NRI v1.20, December 2025), weighted by where residents live; flood claims are shown, not graded. How hazard risk is graded
What stands out about Ann Arbor’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Ann Arbor faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
River and rain flooding
Tornadoes
Strong wind
Shares are of FEMA’s expected building damage, the measure the grade uses; ranks compare each hazard’s building-damage rate with all 85,154 U.S. census tracts. In FEMA’s terms, river and rain flooding is FEMA’s “Inland Flooding” (rivers and streams overflowing their banks, or rain overwhelming drainage). FEMA defines coastal flooding as high or rising tides and storm surge, so surge damage is counted there. Drought isn’t listed: FEMA counts its losses in crops only.
What’s behind Ann Arbor’s grade
River and rain flooding is 66% of the building damage FEMA expects in Ann Arbor, and Ann Arbor’s rate of river and rain flooding damage is lower than 79% of U.S. census tracts. Strong wind adds 8%, at a rate in the top 8% of U.S. census tracts.
A #168 of 701 in Michigan; lower expected damage per building than 88% of U.S. towns (21,298).
Ann Arbor’s residents live in 36 census tracts; FEMA’s figures are combined by where they live.
The typical Michigan town has lower expected damage than 77% of U.S. towns; within the state, Ann Arbor has less expected damage per building than 76% of Michigan towns.
Among the 400 U.S. cities of 100,000 or more, Ann Arbor has lower expected damage per building than 95% (#21 of 400). Because it is so big, its total expected yearly loss, $26.5M, is the 366th largest of those 400.
Does Ann Arbor flood? Sometimes: 34 flood claims since 1980
Every paid claim on a federal flood insurance policy in Ann Arbor, from FEMA’s records: 0.6 per 1,000 homes, fewer than 86% of the 13,809 U.S. towns with a flood insurance record.
Ann Arbor is in FEMA’s Community Rating System (class 6) for its flood-proofing work.
Insurance rates: Washtenaw County.5 federal disasters brought FEMA money to Ann Arbor
Disasters that paid out in Ann Arbor itself (aid to households or repair grants to the City of Ann Arbor), newest first, with that year’s flood claims.
- 2026Severe Storms, Tornadoes, and Flooding31 households applied for aid$28K aid approved
- 2021Severe Storms, Flooding, and Tornadoes309 households applied for aid$154K aid approved1 flood claim paid that year
- 2004Severe Storms, Tornadoes, and Flooding27 households applied for aid$25K aid approved1 flood claim paid that year
- 2000Snow$81K to the City of Ann Arbor for repairs3 flood claims paid that year
- 1999Mi - Severe Weather 1/2 /99$66K to the City of Ann Arbor for repairs1 flood claim paid that year
Washtenaw County has had 8 natural disasters declared by the President since 1953, most often severe storms, then winter storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Ann Arbor after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Ann Arbor archive →Ann Arbor and its neighbors
Ann Arbor is 3rd of the 4 graded towns here, from least expected damage per building to most. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Pittsfield Township | Aless damage than 92% | river and rain flooding | 6 |
| Ann Arbor Township | Aless damage than 90% | river and rain flooding | 1 |
| Ann Arbor | Aless damage than 88% | river and rain flooding | 34 |
| Scio Township | Aless damage than 87% | river and rain flooding | — |
| Barton Hills | — | 430 residents; we grade 1,000+ | |
Hazard risk = FEMA’s expected yearly building damage per dollar of building value, vs. the 21,298 U.S. towns we grade; the map is shaded by fifths of the same scale. Flood claims = paid federal flood insurance claims on record.
Get ready for what Ann Arbor faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- Turn around at flooded roads: a foot of moving water can carry off a car.
- Flood insurance usually takes 30 days to start, so buy it before the forecast.
- Keep papers and medicines up high, in a grab-and-go bag.
- Pick your spot now: the lowest floor, an inside room, no windows.
- A watch means be ready; a warning means take cover now.
- Keep shoes and a flashlight by the bed.
- Trim dead limbs over the house and driveway.
- Tie down trash cans and outdoor furniture.
- Stay clear of downed lines and call the utility.
- Look up the address on FEMA’s flood map.
- Ask the seller or landlord whether it has ever flooded, and what flood insurance costs there.
- Get a flood insurance quote early: policies usually start 30 days after you buy.
- Ann Arbor residents get 20% off flood insurance.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in Ann Arbor
Is Ann Arbor at risk for natural disasters?
On FEMA’s National Risk Index, Ann Arbor has lower expected damage per building than 88% of U.S. towns: A for hazard risk, #168 of 701 in Michigan. Most of the expected damage is river and rain flooding (66%) and tornadoes (20%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Ann Arbor flood?
Flood insurance has paid 34 claims in Ann Arbor since 1980, $782K in all, or 0.6 per 1,000 homes, fewer than 86% of U.S. towns with a flood insurance record. 4 properties have flooded more than once.
Is Ann Arbor in a flood zone?
Flood zones are drawn street by street, so the answer depends on the address: look it up on FEMA’s flood map. In Washtenaw County, 25% of homes in mapped flood zones carry federal flood insurance, and 0.4% of all homes do.
How much is flood insurance in Ann Arbor?
Ann Arbor is in FEMA’s Community Rating System (class 6), which takes 20% off federal flood insurance policies for its flood-proofing work. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
What was the biggest storm in Ann Arbor?
By FEMA money that reached Ann Arbor, Severe Storms, Flooding, and Tornadoes (2021): 309 households applied for aid, $154K approved.
Is Ann Arbor at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (66%), and Ann Arbor’s rate for it is lower than 79% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Ann Arbor.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Ann Arbor’s residents lived in the 2020 census; OpenFEMA: NFIP redacted claims, multiple-loss properties, community status book and residential penetration rates, housing assistance (owners and renters), public assistance funded projects, hazard mitigation properties and disaster declarations. Homes: Census ACS 2020–24. Preparedness tips: Ready.gov. FEMA’s model is an average of expected damage, not a forecast. How hazard risk is graded.