Storm risk in Washtenaw County, Michigan
FEMA's overall hazard score for Washtenaw County is 89.28 (Relatively Moderate), 338th of 3,144 counties. Hail scores 85.85 (Relatively Moderate), strong wind 97.96 (Relatively High) and tornado 96.85 (Relatively High). Expected hail loss is $15 per $1 million of buildings a year; NOAA logged 69 hail reports in Washtenaw County from 2014 to June 2026.
FEMA National Risk Index, version December 2025, retrieved October 8, 2026. NOAA hail reports 2014 to June 2026.
- Washtenaw County, coloured by its FEMA rating
- all U.S. counties
- each county in the state
- U.S. median
- state median
Expected yearly loss per $1 million of buildings, log scale. Dot colour is FEMA’s rating band. The tornado lane counts everything exposed, not only buildings.
How FEMA rates Washtenaw County
| Hazard | Rating | Score (0 to 100) | Rank in U.S. | Rank in MI |
|---|---|---|---|---|
| Overall | Relatively Moderate | 89.28 | 338 of 3,144 | 6 of 83 |
| Hail | Relatively Moderate | 85.85 | 446 of 3,126 | 13 of 83 |
| Strong wind | Relatively High | 97.96 | 65 of 3,126 | 7 of 83 |
| Tornado | Relatively High | 96.85 | 100 of 3,126 | 6 of 83 |
Expected yearly loss, in dollars
| Hazard | This county, total a year | Per $1M of buildings | State median county | U.S. median county | Rank per $1M, U.S. | Rank per $1M, state |
|---|---|---|---|---|---|---|
| Hail | $1,383,782 | $15 | $25 | $22 | 1,809 of 3,126 | 59 of 83 |
| Strong wind | $4,568,086 | $51 | $34 | $20 | 781 of 3,121 | 31 of 83 |
| Tornado | $20,847,641 | $233 | $95 | $199 | 1,357 of 3,144 | 15 of 83 |
Rank 1 is the highest. Overall, hail and wind losses count buildings; the tornado row counts everything FEMA exposes, so it overstates building damage. Expected annual loss is an average over many years for the whole county, not a forecast for one roof.
What stands out in Washtenaw County
- FEMA expects hail in Washtenaw County to cost $15 per $1 million of buildings a year: 0.69 times the U.S. median and 0.63 times the MI county median, ranked 1,809th of 3,126 counties nationally and 59th of 83 in Michigan.
- FEMA expects strong wind in Washtenaw County to cost $51 per $1 million of buildings a year: 2.51 times the U.S. median and 1.51 times the MI county median, ranked 781st of 3,121 counties nationally and 31st of 83 in Michigan.
- FEMA expects tornado in Washtenaw County to cost $233 per $1 million of buildings a year: 1.17 times the U.S. median and 2.47 times the MI county median, ranked 1,357th of 3,144 counties nationally and 15th of 83 in Michigan.
- Applying FEMA's estimate to a $353,000 home, the average yearly loss in Washtenaw County is about $5.47 for hail and $18 for wind before any deductible; at the U.S. median county rates it would be $7.89 and $7.19.
- If the next years look like 2014 to 2025, a roof kept 20 years in Washtenaw County meets about 26.7 hail days of 1 inch or more; the median county in NOAA's file (1,275 counties) would give 35.0.
- Built in 1978, the median home in Washtenaw County is 48 years old, so an original roof has outlived a 3-tab shingle (15 to 20 years) and an architectural one (25 to 30 years); 79.3% of its 158,115 homes are at least 26 years old.
- March to June holds 42 of the 69 hail reports in Washtenaw County (61 percent); the quietest month is January, with 0 reports.
What hail and wind cost a home here in an average year
Enter a home value. The calculator applies Washtenaw County’s own loss rate: the county’s expected yearly loss divided by the value of its buildings. It starts at the Census median home value for the county.
Formula: home value × Washtenaw County yearly loss ÷ building value. Hail: $1,383,782 ÷ $89,377,883,384 = 0.0000155. Wind: $4,568,086 ÷ $89,377,883,384 = 0.0000511. This is FEMA’s estimate of average damage to buildings and does not account for your deductible. Tornado is left out because FEMA’s tornado loss counts people and other exposure, not only buildings.
Read this as a yardstick. The rate is an average over every building in the county, from sheds to office towers, and over many years. Real losses come in rare, large storms; a roof with no damage in 19 years can need full replacement in the 20th. The figure is not a quote and not a prediction for one address.
Washtenaw County in plain numbers
- Washtenaw County scores 89.28 in FEMA's overall hazard index (Relatively Moderate): 338th of 3,144 rated counties and 6th of 83 in Michigan.
- Hail scores 85.85 (Relatively Moderate). FEMA expects $1,383,782 of hail damage to buildings in Washtenaw County a year, which is $15 per $1 million of buildings, 0.69 times the U.S. median.
- Strong wind scores 97.96 (Relatively High) with $4,568,086 of expected yearly building loss in Washtenaw County: $51 per $1 million of buildings, 2.51 times the U.S. median.
- Tornado scores 96.85 (Relatively High) and FEMA's expected yearly tornado loss is $20,847,641, counting everything exposed, or $233 per $1 million of buildings in Washtenaw County.
- FEMA's own event record for Washtenaw County averages 3.14 hail events and 5.70 strong-wind events a year.
- NOAA logged 69 hail reports in Washtenaw County between 2014 and June 2026, on 16 days with stones of 1 inch or more; the largest was 2 inches.
- In Washtenaw County, FEMA counts buildings worth 89.38 billion dollars and 372,064 residents.
- Social vulnerability is Relatively Low in Washtenaw County.
- Community resilience there is Very High, for 372,064 residents.
- 1 city in Washtenaw County is covered on this site: Ann Arbor. 14 Census ZIP areas have more than half of their land in the county.
- Our guide range for a 2,000 sq ft asphalt roof in Ann Arbor is $6,510 to $14,415.
- Washtenaw County ranks 117 of the 194 counties with a page here for hail loss per $1 million of buildings, 19 for wind and 87 for tornado.
- In Washtenaw County, July is the busiest month with 18 of the 69 reports (26 percent), against 0 reports in January.
- Washtenaw County's worst year was 2023, with 3 hail days at 1 inch or more and 16 reports. At the 2014 to 2025 pace that is 1.33 such days a year, one about every 9.0 months.
- The median home in Washtenaw County was built in 1978; 52.9% of its 158,115 housing units date from before 1980, 79.3% from before 2000 and 7.6% from 2010 on.
- Census puts the median home value in Washtenaw County at $353,000, and 61.6% of homes are lived in by their owners.
- 6,739 single-family building permits were issued in Washtenaw County from 2014 to 2025, about 42.6 per 1,000 homes, peaking in 2021.
- NOAA lists 2 tornado tracks in Washtenaw County since 2014; the strongest was an EF1 on June 23, 2015 near Rowes Corner, 4.33 miles long.
- The fastest gust in NOAA's records for Washtenaw County is 75 mph on May 13, 2014 at Ann Arbor.
- The nearest county with a page here is Ingham County, 36 miles from the centre of Washtenaw County; its hail score is 92.56.
- Across counties the median is one roofing firm for every 5,189 homes; Census counted 16 roofing contractor establishments in Washtenaw County in 2023, one for every 9,882 homes.
The hail record of Washtenaw County, year by year
NOAA logged 69 reports in Washtenaw County; hail of 1 inch or more fell on 16 days. That is 1.3 such days a year; the median county in NOAA’s file has 1.8.
- reports
- days with hail of 1 inch or more
- * 2026 runs to June only
Reports by calendar month, all years together. Peak: July, 18 reports.
The same numbers as a table (years with at least one report)
| Year | Reports | Days, 1 inch or more | Days, 1.75 inch or more | Largest stone | Damage reported |
|---|---|---|---|---|---|
| 2014 | 7 | 1 | 0 | 1 in | – |
| 2015 | 14 | 1 | 1 | 2 in | – |
| 2016 | 5 | 1 | 0 | 1 in | – |
| 2017 | 8 | 3 | 0 | 1.25 in | – |
| 2018 | 4 | 1 | 0 | 1 in | – |
| 2019 | 4 | 2 | 0 | 1.5 in | – |
| 2020 | 4 | 1 | 0 | 1.5 in | – |
| 2021 | 3 | 1 | 0 | 1 in | – |
| 2023 | 16 | 3 | 2 | 2 in | $1,000,000 |
| 2024 | 2 | 1 | 0 | 1 in | – |
| 2025 | 1 | 1 | 0 | 1 in | – |
| 2026 (to June) | 1 | 0 | 0 | 0.88 in | – |
Biggest hail days in Washtenaw County
| Date | Largest stone | Reports that day | Damage reported | Near |
|---|---|---|---|---|
| May 27, 2015 | 2 in | 14 | none recorded | Hudson Mills |
| July 20, 2023 | 2 in | 3 | none recorded | Ypsilanti |
| June 15, 2023 | 1.75 in | 10 | $1,000,000 | Delhi Mills |
| April 7, 2020 | 1.5 in | 4 | none recorded | Ann Arbor Young Arpt |
| March 14, 2019 | 1.5 in | 3 | none recorded | Sylvan |
Where large hail was reported
FEMA scores the county as a whole. NOAA’s reports show where inside Washtenaw County the big stones fell.
Reported hail locations, Washtenaw County
- 411 to 1.74 in
- 41.75 to 2.74 in, golf ball to tennis ball
- 02.75 in and up, baseball
Largest plotted stone: 2 in. Bigger dots are bigger stones.
45 reports of 1 inch or larger have coordinates. Each dot is a reported location, not a storm path.
Sources: NOAA, Census county outlineWind and tornado records for Washtenaw County
Fastest gusts in Washtenaw County
| Date | Gust | Near |
|---|---|---|
| May 13, 2014 | 75 mph | Ann Arbor |
| September 5, 2014 | 74 mph | Whittaker |
| August 24, 2020 | 71 mph | Ypsilanti |
| September 5, 2014 | 70 mph | Rawsonville |
Strongest tornado tracks in Washtenaw County
| Date | Scale | Length | Injured / killed | Near |
|---|---|---|---|---|
| April 15, 2026 | EF1 | 1.71 mi | 0 / 0 | Ann Arbor |
| June 23, 2015 | EF1 | 4.33 mi | 0 / 0 | Rowes Corner |
2 tornado tracks in all since 2014; the strongest 2 are listed.
How old the roofs are
Census counts homes by the decade they were built. Under each bar is the number of hail days of 1 inch or more that an original roof from that decade has met, at Washtenaw County’s 2014 to 2025 pace of 1.33 such days a year. Most roofs have been replaced since; the row shows what a roof that never was would have taken.
Bars: share of 158,115 housing units by decade built. Figures under the decade: hail days met by an original roof, at the county’s 2014 to 2025 pace. The pace of earlier years is unknown.
| Median year built | 1978 |
| Built before 1980 | 52.9% |
| Built before 2000 | 79.3% |
| Built since 2010 | 7.6% |
| Owner-occupied | 61.6% |
| Median home value | $353,000 |
| Single-family permits, 2014 to 2025 | 6,739 |
| Permits per 1,000 homes | 42.6 |
Asphalt shingles are rated 15 to 20 years (3-tab) and 25 to 30 years (architectural). Source: Census ACS 2019 to 2023 and Building Permits Survey.
Roofers and past disasters in Washtenaw County
Roofing firms in Washtenaw County
| Roofing contractor establishments, 2023 | 16 |
| Change since 2016 | +2 (+14%) |
| Homes per roofing firm | 9,882 |
| Median across counties | 5,189 |
| Employees, 2023 | 121 |
Source for Washtenaw County: Census County Business Patterns, NAICS 238160.
Nearby counties
The closest counties that have a risk page, by distance between county centres. Loss is per $1 million of buildings; the columns marked "times here" divide the neighbour's loss by Washtenaw County's.
| County | Miles | Overall | Hail loss | Hail, times here | Wind loss | Wind, times here | NOAA hail reports |
|---|---|---|---|---|---|---|---|
| Ingham County, MI | 36 | Relatively Moderate | $39 | 2.49 | $87 | 1.70 | 17 |
| Genesee County, MI | 52 | Relatively Moderate | $21 | 1.36 | $53 | 1.04 | 21 |
| Calhoun County, MI | 60 | Relatively Low | $58 | 3.74 | $87 | 1.70 | 8 |
| Saginaw County, MI | 76 | Relatively Moderate | $26 | 1.68 | $73 | 1.42 | 21 |
| Kalamazoo County, MI | 87 | Relatively Moderate | $105 | 6.78 | $35 | 0.69 | 14 |
| Kent County, MI | 102 | Relatively Moderate | $5.56 | 0.36 | $29 | 0.56 | 18 |
More Michigan counties, nearest first
- Muskegon County 137 mi
Cities and ZIP areas in Washtenaw County
1 city in this county is on PickARoofer. ZIP Code Tabulation Areas are Census shapes that approximate ZIP codes; where we have a city’s ZIPs, the share is the part of each area’s land that lies in this county. 14 such areas have more than half their land here.
| City | ZIP areas (share of land in the county) | Pages |
|---|---|---|
| Ann Arbor | 48104 (100%), 48103 (100%), 48109 (100%), 48105 (100%) | Roofers |
Storm hit your roof in Washtenaw County? A free inspection tells you if there is damage. One local roofer answers, not five.
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How high is storm risk in Washtenaw County?
FEMA's National Risk Index gives Washtenaw County an overall score of 89.28 (Relatively Moderate), 338th of 3,144. Hail scores 85.85 (Relatively Moderate), strong wind 97.96 (Relatively High) and tornado 96.85 (Relatively High).
In Washtenaw County, how many hail reports has NOAA logged?
A report is one entry for one storm in one county, so counts follow where people live as well as where hail fell. NOAA has 69 for Washtenaw County between 2014 and June 2026, on 16 days with hail of 1 inch or more; the largest stone was 2 inches.
What do hail and wind cost a home in Washtenaw County each year, on average?
Applying FEMA's county rates to its median home value of $353,000: FEMA's estimate is about $5.47 a year for hail and $18 for wind, before any deductible, against $7.89 and $7.19 at the U.S. median county rates. This is an average over many years and all buildings, not a prediction for one roof; one bad storm costs far more than the average year.
How does Washtenaw County compare with the rest of Michigan?
Per $1 million of buildings Washtenaw County loses $15 to hail a year, against $25 in the median county of the state. Among 83 rated counties it is 13th for hail, 7th for strong wind and 6th for tornado.
How old are the roofs in Washtenaw County?
The median home was built in 1978, 48 years ago, and 79.3% of the 158,115 housing units in Washtenaw County date from before 2000. Asphalt shingles are rated 15 to 20 years (3-tab) or 25 to 30 years (architectural), so an original roof of either kind is past its rated life. The Census does not record when a roof was replaced.
What does expected annual loss mean?
It is FEMA's estimate of the average yearly loss from a hazard, in dollars, summed over the county. It is built for comparing counties at planning level, not for pricing one house.
Does a high rating mean my roof will be damaged?
No. The index compares counties and cannot say what will happen on your street. After a storm, a roof inspection is the only way to know.
Sources for Washtenaw County: FEMA National Risk Index, version December 2025, retrieved October 8, 2026; NOAA Storm Events Database hail reports for Washtenaw County; Census Bureau ZCTA-to-county relationship file (2020); Census ACS and Building Permits Survey, homes in Washtenaw County; Census County Business Patterns, roofing firms in Washtenaw County. Planning-level information about Washtenaw County, not an inspection and not insurance advice.
This product uses the Federal Emergency Management Agency's National Risk Index dataset 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).