Delaware County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Delaware County: 4.
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.

Every storm within 100 miles

1. Tropical storms and hurricanes (34 kt or more, still tropical) at closest approach. Post-tropical remnants with gale-force winds are listed but not counted. Direct: track within 50 miles; near: within 100 miles. Distance is measured to the county boundary for counties and to the city centre for cities, using positions interpolated hourly between HURDAT2 fixes.

National Hurricane Center HURDAT2, 1851 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.

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. Apr 20, 2003Hail$65.0 million
   National Weather Service narrative

   Hail up to the size of golf balls affected the north side of the Columbus metro area and southern Delaware county. Hail was extensive from Dublin, through Worthington and Powell, to Westerville. Trees and shrubs were stripped of their foliage and cars and homes sustained significant hail damage. The hail covered the ground in some locations up to six inches deep in Worthington in northern Franklin county and near the Polaris Mall in southern Delaware county.

2. Sep 14, 2008High Wind, Delaware$18.4 million
   National Weather Service narrative

   Strong winds of 40 to 50 miles per hour were sustained for several hours. Gusts over 60 mph were common. Widespread damage occurred across the region, from trees being blown down on powerlines, to significant crop losses and structural damage. A man was electrocuted at the Scioto juvenile correctional facility while operating a generator.

3. Sep 20, 2000Tornado$1.0 million
   National Weather Service narrative

   A tornado touched down in the southeastern part of the county, along Harlem road and then raced rapidly eastward to the Licking county line. Two high tension power line towers were bent over and 14 houses were either damaged or destroyed.

4. Mar 14, 2024Tornado$1.0 million
   National Weather Service narrative

   The tornado developed in central Delaware County near U.S. Route 23. As the tornado crossed U.S. Route 23, it strengthened and widened and caused more widespread structural damage as it crossed the Olentangy River. Even more significant damage occurred as it moved along Berlin Station Road and in other areas of Berlin Township. Along this portion of the track, a number of homes sustained siding and roof damage and numerous trees were snapped and uprooted. Several barns were also destroyed. In the vicinity of Olentangy Berlin High School, parts of the school campus and athletic fields were damaged, signs were bent over, and several free-standing transmission towers were felled. In…

5. Jul 18, 1996Lightning$620,000
   National Weather Service narrative

   Lightning struck a free-standing garage causing extensive damage.

6. Jan 6, 1996Winter Storm, Delaware$500,000
   National Weather Service narrative

   The Blizzard of '96 developed near the Gulf Coast and moved up the East Coast. This massive system produced the greatest total and 24 hour snowfall at Greater Cincinnati\Northern Kentucky airport. This one storm brought 14.3 inches of snowfall to the airport which normally receives 23 inches for an entire season. The heaviest snow fell near the Ohio river in the extreme south. The worst blizzard conditions occurred over West Central areas as dry and powdery snow was blown around by high winds causing whiteouts. Some areas had more than 30 continuous hours of snowfall, and many people in Southern Ohio felt this was the worst winter storm since the Blizzard of '78. In Fayette…

7. Jun 15, 2004Flash Flood$250,000
   National Weather Service narrative

   As much as five inches of rain caused severe flooding in and around Delaware. 154 homes were damaged, many in subdivisions along State Route 257 northwest of Powell. 34 mobile homes in the Shroyers Mobile Home Park just north of Delaware sustained damage when the Olentangy River rose out of its banks, and forced a few evacuations. Numerous roads and bridges were damaged by high water and culvert washouts.

8. Jun 13, 2013Tornado$200,000
   National Weather Service narrative

   The tornado briefly touched down on the west side of Highway 257 southwest of Radnor. The tornado initially hit two barns, destroying one and heavily damaging another. One barn consisted of cinder block walls and tin roofing. Much of the cinder block collapsed, while roofing of this structure with some of the attached cinder block and other bard roofing and walls was lifted across Highway 257 where much of the material was wrapped around trees along the Scioto River. Large portions of the barn roofing was lofted over the tree line along the Scioto River and deposited in the back yards of residences along River Road, on the east side of the river, a distance of two tenths of a mile…

9. Feb 21, 2014Tornado$100,000
   National Weather Service narrative

   The tornado touched down on the edge of a field along North Old State Road. A large tree and barn sustained significant damage near the beginning of the path of the tornado. The tornado then moved northeast, crossing North Old State Road. A narrow path of additional tree damage was observed in the front yard of a residence. This home sustained minor damage including a garage door blown in, loss of shingles and a couple of broken windows. A nearby utility pole and transformer were snapped with electric lines also downed. Further along the path of the tornado, a large spruce tree was uprooted, an unanchored storage shed was moved off its foundation, and several other trees were…

10. Jun 1, 1997Flash Flood$100,000
    National Weather Service narrative

    From 4-7 inches of rain fell from late on May 31st until the night of June 1st, with flooding occurring as thunderstorms trained across the county during the evening. Numerous roads were flooded especially in the southern half of the county.

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

104°FJul 14, 1954

All-time low

−22°FJan 19, 1994

Warmest night

79°FJul 30, 1999

Coldest day

−5°FJan 20, 1985

Wettest day

5.13 inJul 13, 1992

Snowiest day

15.5 inMar 8, 2008

Hottest year

2024mean 57.3°F

Coldest year

1976mean 49.6°F

Wettest year

201855.18 in

Driest year

196324.51 in

Snowiest season

56.4 in2013-14

Station John Glenn International Airport (USW00014821), 810 ft elevation, 17.0 miles from the population centre. Daily records from 1948 to October 26, 2026; 100.0% 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 USW00014821.
• 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.