Washtenaw County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Washtenaw County: 1.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Smoke overhead

1. A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.

NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.

Claims by ZIP code

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).

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

River crests

River gauges

1. Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.

NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

Every earthquake of magnitude 4 or more within 50 miles

1. Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
2. Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).

USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.

Mapped landslides

Mapped by NASA (1).

1. Landslides mapped in the USGS compilation of landslide inventories across the United States (version 3.0, 2025), rated probable or better. The compilation joins inventories made by federal and state agencies for different purposes and areas, so the number mapped in a county reflects how closely it has been surveyed as much as how often its slopes fail. An area with few records may simply not have been mapped. Deaths are as recorded in the inventories; a slide listed in two inventories is counted once.

USGS Landslide Inventories across the United States, version 3.0, retrieved October 27, 2026.

More event types since 1996

Costliest events since 1996

1. Mar 8, 2017High Wind, Washtenaw$25.0 million
   National Weather Service narrative

   A non thunderstorm event took place over the state on Wednesday, March 8, 2017, as high winds brought wind gusts in excess of 60 mph! The high winds took out power lines and trees, along with numerous reports of structural damage to buildings. There were also reports of brush fires and tractor-trailers flipped over around the area. Due to the extensive damage, many areas were without power for several days. Approximately 800,000 DTE customers and approximately 300,000 Consumers Energy customers were affected. The highest wind gust reported across Southeast Michigan was 68 mph at both Saginaw and Detroit Metro Airport.

2. Mar 15, 2012Tornado$12.0 million
   National Weather Service narrative

   A National Weather Service Storm Survey confirmed an EF-3 tornado touched down near Dexter, MI with maximum wind speeds of 135-140 mph. The path length was 7.6 miles with a maximum width of 800 yards. The tornado touched down at 5:18 pm just northeast of the intersection of N Territorial and Dexter Townhall Rd. The tornado moved southeast and produced EF-1 damage with winds estimated at 100 mph. Damage was limited to uprooted and snapped trees as well as minor roof damage. The tornado strengthened as it hit the Horseshoe Bend Subdivision with winds estimated at 120 mph and structural damage to the outside of homes. The tornado then continued to track southeast alongside…

3. Feb 22, 2023Ice Storm, Washtenaw$8.0 million
   National Weather Service narrative

   A major winter storm impacted Southeast Michigan during the daytime and evening hours of February 22, 2023. Warm/moist air originating in the Gulf of Mexico surged north toward a surface warm front, increasing coverage and intensity of precipitation over lower Michigan by mid-morning. This warmer air aloft interacted with a resident cold airmass near the surface, creating conditions favorable for snow to the north and a wintry mix for much of the metro Detroit region. The higher snow accumulations occurred across areas well north of I-69, with Midland, Bay, Tuscola, and Huron counties reporting 5 to 9 inches. Communities along and south of I-69 saw a wintry mix of snow, sleet, and…

4. Jun 25, 2021Flash Flood$7.5 million
   National Weather Service narrative

   Numerous roads became impassable due to flash flooding. Parts of Ann Arbor received around 5.5 inches of rainfall, with Ypsilanti reporting the highest total of 6.76 inches. Around 3 inches of rainfall was reported near Saline and Dexter. Forty-four homes suffered major flood damage, while 127 homes experienced flood damage across the county.

5. Apr 14, 2018Winter Storm, Washtenaw$6.0 million
   National Weather Service narrative

   A large and complex low pressure system impacted the Great Lakes region. Southeast Michigan saw heavy rain, snow, sleet and freezing rain that began on Friday (April 13) and lasted through Sunday (April 15). This system brought 2 main periods of precipitation, with a short break in between on Saturday. Total rainfall of 1 to 2 inches was common in many locations in Southeast Michigan, with 2-3 of snow and sleet north of I-69, and about 1/4 to 1/2 of ice from freezing rain between the I-94 and I-96 corridors. Widespread tree damage and power outages from an combination of the snow, sleet, and freezing rain occurred. In total, DTE and Consumers Energy reported power outages for…

6. Jul 21, 1998Thunderstorm Wind$4.5 million
   National Weather Service narrative

   July 21st was one of the hottest days of the summer in southeast Michigan, as temperatures soared into the middle to upper 90s. An extremely humid airmass was also in place, with dew points in the upper 70s. The above produced an extraordinarily unstable atmosphere, with CAPE values approaching 7000 J/kg. A weak trough of low pressure moved east into western lower Michigan during the afternoon. It was on this trough that thunderstorms first developed. Thanks to the amount of instability present, these storms rapidly became severe. Winds aloft were rather strong for mid-summer, with 40 knot winds less than a mile above ground level (at 850 mb). Thus, the storms were prodigious…

7. Feb 19, 2016High Wind, Washtenaw$4.0 million
   National Weather Service narrative

   Strong southwest winds of 50 to 60 mph brought down trees...tree limbs...and power lines...mainly along the M-59 corridor and I-94 corridors of Southeast Michigan. DTE reported 117,000 customers were affected during the peak early Friday evening, with 75,000 customers remaining without power into Saturday the next day. |Here are some of the higher wind gusts reported at airports across the area on Friday February 19th:|Ypsilanti... 58 mph at 1022 PM.|Detroit Metro... 55 mph at 744 PM.|Owosso... 55 mph at 835 PM.|Saginaw (MBS)... 54 mph at 536 PM.|Pontiac... 54 mph at 742 PM.|Ann Arbor... 54 mph at 719 PM.|Flint Bishop... 53 mph at 634 PM.|Howell... 53 mph at 734 PM.|Detroit…

8. May 4, 2018High Wind, Washtenaw$4.0 million
   National Weather Service narrative

   A strong low pressure system tracked through northern Lower Michigan, swinging a strong cold front through southeast Michigan early in the afternoon. Sustained winds ranging between 30 - 40 mph, with frequent gusts in the 45 to 60 mph range, with scattered thunderstorms that developed leading to enhanced winds near 70 MPH. Downed large trees, branches, telephone and power lines were reported across all counties in Southeast Michigan, with around 230,000 customers without power during the peak. In Independence Township, a large tree fell onto a car, killing the 36 year old man inside. Additionally, a postal employee in South Lyon was also seriously hurt when a tree fell on him as…

9. Dec 28, 2008High Wind, Washtenaw$3.0 million
   National Weather Service narrative

   A rapidly deepening low pressure system tracked northeast from northern Lake Michigan, sending a strong cold front through southeast Michigan. Winds gusts of 50 to 65 mph behind the cold front lead to widespread tree branches and trees downed, along with extensive power outages, as more than 400,000 Michigan homes and businesses lost power. The majority of those customers who lost power were located in the Detroit Metro Area.

10. Mar 13, 1997Ice Storm, Washtenaw$3.0 million
    National Weather Service narrative

    Low pressure tracked from the central Plains northeast across southeast lower Michigan late on the 13th through the 14th. The storm brought widespread precipitation to southeast Michigan from late on the 13th through midday on the 14th. North of Detroit, nearly all of the precipitation fell in the form of freezing rain, with small amounts of snow and sleet noted in a few spots. From Detroit and Ann Arbor south to the state-line, the freezing rain changed to rain, but not before heavy ice accumulations occurred. Total precipitation amounts ranged from 1.5 to nearly 2.5 inches from Detroit and Ann Arbor south to the Ohio state-line. From the northern suburbs of Detroit north to…

1. Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.

NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.

All-time high

105°FJul 24, 1934

All-time low

−22°FJan 19, 1994

Warmest night

80°F3 times, most recently Jun 25, 1952

Coldest day

−5°FJan 19, 1994

Wettest day

4.54 inAug 6, 1998

Snowiest day

15.8 inDec 1, 1974

Hottest year

2012mean 53.4°F

Coldest year

1917mean 44.4°F

Wettest year

201151.03 in

Driest year

196316.85 in

Snowiest season

97.1 in2013-14

Station Ann Arbor U Of Mich (USC00200230), 813 ft elevation, 4.3 miles from the population centre. Daily records from 1891 to October 26, 2026; 99.9% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.

NOAA NCEI Global Historical Climatology Network Daily.

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).

OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.

Neighbouring counties

• Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
• Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
• Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
• Storm events NOAA NCEI Storm Events Database, through 2026.
• Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
• Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
• Weather records NOAA NCEI Global Historical Climatology Network Daily, station USC00200230.
• River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
• Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
• Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
• Landslides USGS Landslide Inventories across the United States, version 3.0 (2025).
• Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.

Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.