Williams County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Williams County: 0.
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.

More event types since 1996

Costliest events since 1996

1. May 17, 1996Flash Flood$3.0 million
   National Weather Service narrative

   Up to ten inches of rain fell across Williams County in a 6 hour period producing serious flooding in many communities in Williams County. The hardest hit communities were Bryan, Ohio and Antwerp, Ohio. Flooding in the county was described as the worst in 70 years. In Antwerp 22 homes were damaged with 11 beyond repair. In Bryan, Ohio water as deep as 8 foot was reported in places with many homes sustaining damage and some beyond repair. Total damage to property, roads and utilities was estimated at 3 million dollars.

2. Jun 23, 2010Thunderstorm Wind$200,000
   National Weather Service narrative

   An intense microburst with estimated winds at 100 mph was surveyed in the town of Edgerton. A large portion of the upper story of the old town hall building next to the fire department was blown in with loss of much of the roof. Debris from this structure damaged nearby vehicles and the flea market building across the street including a portion of the south-facing wall getting blown out. One person was injured at this location from falling debris. In addition, a freight container was blown off an intermodal train and there was significant tree damage in town. Wind damage path was about 3 miles long and a quarter of a mile wide.

3. Jun 19, 2002Lightning$150,000
   National Weather Service narrative

   Newspaper report of lightning striking home and entering kitchen through electrical service. Fire started in kitchen and spread through the home.

4. Jun 9, 2008Thunderstorm Wind$75,000
   National Weather Service narrative

   Local law enforcement officials reported numerous trees down across the county. Many of these were in a swath from Edon northeast to Kunkle. A tree fell onto a house in the town of Kunkle with trees onto several cars in West Unity. Damage is estimated at $75,000.

5. May 9, 2000Thunderstorm Wind$40,000
6. Aug 24, 1998Thunderstorm Wind$20,000
   National Weather Service narrative

   THE FRONTIER CABLEVISION BUILDING LOST PART OF ITS ROOF.

7. Nov 6, 2005Thunderstorm Wind$20,000
   National Weather Service narrative

   Trees and power lines were blown down across the county.

8. Jun 27, 2007Thunderstorm Wind$20,000
   National Weather Service narrative

   Trees were reported down in and around Pioneer. A few trees fell onto vehicles trapping the occupants. No injuries were reported.

9. Jun 21, 2006Thunderstorm Wind$20,000
   National Weather Service narrative

   Trees, tree limbs and power lines were reported down across the county.

10. Aug 25, 1998Thunderstorm Wind$20,000
    National Weather Service narrative

    A LINE OF LARGE UTILITY POLES WERE SNAPPED OR BLOWN DOWN.

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

111°FJul 25, 1934

All-time low

−26°FJan 13, 1912

Warmest night

79°F2 times, most recently Jul 5, 2012

Coldest day

−10°F2 times, most recently Jan 19, 1994

Wettest day

4.63 inSep 18, 1907

Snowiest day

12.0 in3 times, most recently Feb 16, 2021

Hottest year

2012mean 53.9°F

Coldest year

1978mean 46.4°F

Wettest year

201155.27 in

Driest year

194121.54 in

Snowiest season

75.4 in2013-14

Station Defiance (USC00332098), 700 ft elevation, 20.1 miles from the population centre. Daily records from 1893 to October 25, 2026; 98.2% 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 USC00332098.
• 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.
• 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.