| April 1965 | Tornado (F2) | not stated | 4 killed, 35 hurt, $2,500,000 | no account filed |
| July 2017 | Thunderstorm Wind | Troyton | 3 hurt, $5,000 | A camper trailer was overturned at Delaware State Park. A tree also fell onto a tent of campers. |
| September 2000 | Tornado (F2) | Harlem | 2 hurt, $1,000,000 | 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. |
| September 2010 | Thunderstorm Wind | Powell | 1 hurt, $40,000 | Trees were reported down around the area due to damaging thunderstorm winds. A portion of the roof was peeled off of the Olentangy High School gym. One woman was injured when a tree fell onto her home causing severe damage to the roof. The woman was taken to a nearby hospital for possible concussion. |
| July 1994 | Thunderstorm Wind | Delaware | 1 hurt, $5,000 | Trees and limbs were downed, at least one falling on a house. Outbuildings were damaged. A 36 year-old man had to be hospitalized after lightning hit the barn he was in as he sat in a metal chair. |
| August 1958 | Tornado (F1) | not stated | 1 hurt | no account filed |
| April 2003 | Hail | Powell | $65,000,000 | 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. |
| March 2024 | Tornado (EF1) | Stratford | $1,000,000 | 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 this area, maximum wind speeds were estimated to be around 110 mph.||The tornado crossed Alum Creek Reservoir and moved into neighborhoods southwest of Sunbury and west of Galena, where it caused widespread and significant tree damage and a large number of homes had windows blown out, roofs partially removed, and power poles snapped. Damage in these areas was consistent with wind speeds from 95 to 105 mph. ||As the tornado moved through the Galena area, there was a complex mix of straight-line wind damage through southern parts of the town of Galena with tornadic damage embedded across the north side of Galena. The damage field through this area was notably wide.||The tornado entered Licking County at 2022EST, about 3 miles SSE of Condit, and continued to moved east-southeast across much of northern Licking County before ending at 2050 EST, about 1 mile south-southeast of St. Louisville. |
| July 1996 | Lightning | Delaware | $620,000 | no account filed |
| July 1994 | Thunderstorm Wind | Ashley | $500,000 | Trees were downed. Twenty sailboats capsized in O'Shaughnessy Reservoir (Shawnee Hills area) during the storm. Many boaters had to be rescued from the water well off shore. |
| June 2004 | Flash Flood | Delaware | $250,000 | 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. |
| April 1978 | Tornado (F1) | not stated | $250,000 | no account filed |
| June 2013 | Tornado (EF0) | Radnor | $200,000 | 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 away. Tree damage along the south side of the brief tornado track was lying in a northeast orientation which was inward toward the tornado track which confirms the convergent circulation. Other damage along the path included snapped large trees, complete destruction of a small shed, and large amounts of debris wrapped around trees. Corn stalks were found in yards of residence on the east side of the Scioto River, with the nearest corn fields nearly a quarter of a mile away. Based on the damage surveyed, the maximum wind speed of this tornado was approximately 85 miles per hour. |
| February 2014 | Tornado (EF0) | Kilbourne | $100,000 | 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 damaged. Based on the damage surveyed, the maximum estimated wind speed of this tornado was 85 miles per hour. |
| June 1997 | Flash Flood | Countywide | $100,000 | 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. |
| May 1997 | Thunderstorm Wind | Delaware | $100,000 | Numerous trees downed. Six homes were damaged when trees fell on them. |
| March 2024 | Tornado (EF1) | Ostrander | $50,000 | The tornado initially developed in Union County, at 1924EST, about 1.3 mile west of Lunda. The tornado moved east-southeast and entered Delaware County at 1948EST, about 2 miles northwest of Ostrander. As the tornado moved east across far western, it produced mainly tree damage before ending near U.S. Route 36. |
| June 2022 | Thunderstorm Wind | Delaware | $50,000 | Numerous trees and power lines were downed throughout Delaware County. |
| September 2000 | Thunderstorm Wind | Galena | $50,000 | Thunderstorm winds caused damaged to a home and 2 houses under construction. |
| August 1997 | Tornado (F0) | Sunbury | $50,000 | A tornado made a brief touchdown damaging numerous trees, destroying a barn, damaged 2 homes, and carried away a swingset. |
| July 1995 | Thunderstorm Wind | Countywide | $40,000 | A strip mall under construction in southern Delaware County along Ohio Route 750 sustained extensive damage due to thunderstorm winds. Winds to 58 mph were measured in Delaware, and numerous power lines and trees were downed at several locations. Some trees fell onto vehicles and across roads. |
| April 2024 | Tornado (EF1) | Harlem | $35,000 | The tornado quickly developed and likely reached the maximum intensity near the intersection of Fancher Road and State Route 605 South causing damage to a residence on the south side of Fancher Road. Multiple homes on the south side of Fancher Road had damage including blown out windows, garage door failures, and moderate roof material loss.||The tornado weakened as it crossed Fancher Road near Hatch Road and Kean Road, causing damage to trees in the area. The last known damage was found north of Fancher Road where an outbuilding lost most of its metal panels. |
| September 2020 | Tornado (EF0) | Kilbourne | $25,000 | The tornado is believed to have begun in a field just west of Jumper Road, with the first evidence of tornadic damage occurring along Jumper Road. Multiple trees and large limbs were knocked down and partial uplift of a roof was observed on one of the homes. Shingles and other material were thrown both downwind and upwind from the home. To the southeast of Jumper Road, additional tree damage was noted along North Old State Road. The tornado likely crossed Alum Creek, producing additional tree damage along N 3 Bs and K Road before lifting. This tornado was rated EF0 on the Enhanced Fujita Scale, with maximum winds of 80 mph. |
| April 2014 | Thunderstorm Wind | Delaware | $25,000 | A roof was blown off of a structure in Delaware due to thunderstorm winds. |
| July 2013 | Thunderstorm Wind | Delaware | $25,000 | Several large trees were downed due to thunderstorm winds. A dugout collapsed at Delaware Christian sporting fields. |
| August 2016 | Tornado (EF0) | Delaware | $20,000 | A weak tornado initially touched down just south of the Buckeye|Valley Middle School. The damage near the school was limited to|one tree with a limb down. The track continued north-northeast|into a residential area. In this residential area several 2 to 4|inch limbs were snapped and a few shallow-rooted trees were|uprooted. Roof damage was observed due to a fallen tree on Coover|Road and a barn had part of the roof cave in on its east side.||The tornado lifted until it crossed US-23 just west of Delaware|Dam. A small cluster of trees were twisted on the west side of the|highway.||The next location is Delaware State Park where the tornado was on|the ground for a few minutes. At Delaware State Park, a few|partially rotten large limbs were downed and numerous 2 to 3 inch|limbs were also downed. Also, several shallow rooted trees were|uprooted. A medium-sized dumpster near the marina was tipped and|moved about 20 feet. Three boats at the marina sustained minor|awning damage. A few 2 to 3 inch tree limbs around the marina were|snapped. Across the river from the marina, a snapped limb marked|the end of the tornado track. |
| July 2011 | Flash Flood | Center Vlg | $20,000 | Roads were closed due to high water caused by heavy rain. Some driveways were washed out. |
| September 2011 | Thunderstorm Wind | Delaware | $20,000 | A two to three foot diameter tree was reported down. Several tree limbs fell on cars. Railroad crossing arm guard equipment was damaged. These occurrences were due to damaging thunderstorm winds. |
| July 2003 | Thunderstorm Wind | Powell | $20,000 | Numerous trees and large limbs up to four inches in diameter were downed near the Polaris Mall. |
| July 1997 | Thunderstorm Wind | Delaware | $20,000 | Roof peeled off a barn and numerous trees downed. |
| July 1996 | Lightning | Cheshire | $20,000 | no account filed |
| June 2011 | Thunderstorm Wind | Ostrander | $15,000 | Trees were down, a barn roof was blown off, and wood was driven into the siding of a house due to damaging thunderstorm winds. |
| August 2010 | Thunderstorm Wind | Delaware | $15,000 | Two tractor trailers were blown over and shingles were ripped off of a house due to damaging thunderstorm winds. |
| November 2003 | Thunderstorm Wind | Ashley | $15,000 | A barn was destroyed and numerous trees were downed along North Old State Road. |
| November 1996 | Thunderstorm Wind | Radnor | $15,000 | no account filed |
| July 2023 | Thunderstorm Wind | Stratford | $10,000 | Several trees and power lines were downed. |
| July 2023 | Thunderstorm Wind | Shawnee Hills | $10,000 | A large tree fell onto a house. |
| July 2022 | Thunderstorm Wind | Sunbury | $10,000 | Several trees and power lines were downed. |
| July 2022 | Thunderstorm Wind | Sunbury | $10,000 | Several trees were downed in the Sunbury area as well as in other parts of eastern Delaware County. |
| June 2022 | Thunderstorm Wind | Olive Green | $10,000 | A roof was ripped off of a barn and multiple trees were also downed on the property. |
| June 2022 | Thunderstorm Wind | Cheshire | $10,000 | Several trees were downed and two roofs were damaged. |
| July 2020 | Thunderstorm Wind | Sunbury | $10,000 | Numerous trees and power lines were downed in the Sunbury area. |
| September 2020 | Thunderstorm Wind | Delaware | $10,000 | Several trees and wires were downed in and near the city of Delaware. |
| July 2017 | Thunderstorm Wind | Leonardsburg | $10,000 | Several trees and power poles were downed along Horseshoe Road. A tin garage roof was removed from a residence near the intersection of Horseshoe Road and Bishop Road. |
| November 2013 | Thunderstorm Wind | Hyatts | $10,000 | A tree was reported down on a car with people inside. No injuries occurred. |
| June 2012 | Thunderstorm Wind | Delaware | $10,000 | Trees and power lines were downed due to damaging thunderstorm winds. |
| July 2012 | Thunderstorm Wind | Delaware | $10,000 | There were numerous reports of downed trees in Delaware County due to damaging thunderstorm winds. |
| June 2008 | Thunderstorm Wind | Ashley | $10,000 | Shingles were blown off of the roofs of several homes. Yard furniture was displaced in the backyard of one of the homes. |
| May 2004 | Hail | Delaware | $10,000 | Trees were also knocked down near the intersection of State Route 37 and Houk Road. |
| September 2000 | Flash Flood | Berkshire | $10,000 | Heavy rainfall caused flooded roads. |
| May 1998 | Thunderstorm Wind | Powell | $10,000 | Winds gusted to 70 mph downing trees and power lines. |
| May 1995 | Thunderstorm Wind | Berkshire | $10,000 | Measured winds of 60 miles an hour knocked down several large trees, some feel on power lines and across roads. Ten thousand three hundred people temporarily lost power. |
| January 1997 | Thunderstorm Wind | Genoa Twp | $10,000 | no account filed |
| July 2023 | Thunderstorm Wind | Delaware | $8,000 | Several trees were downed across mainly western portions of Delaware County. |
| August 2021 | Thunderstorm Wind | East Liberty | $8,000 | Several trees were downed. A house was also struck by lightning. |
| June 2011 | Thunderstorm Wind | Sunbury | $8,000 | Numerous power lines were reported down and a tree fell through the roof of a house due to damaging thunderstorm winds. |
| January 2008 | Thunderstorm Wind | Delaware | $8,000 | A street lamp was blown down. A house sustained siding damage and had roof shingles peeled off in the same neighborhood. |
| June 2006 | Thunderstorm Wind | Delaware | $8,000 | Several tents were blown down at the Delaware County Fairgrounds. Trees were also downed. |
| July 2003 | Thunderstorm Wind | Radnor | $8,000 | Numerous trees down across the northern part of the county. |
| June 2000 | Thunderstorm Wind | Countywide | $7,000 | Trees were reported down across the southern half of the county. |