| August 2009 | Thunderstorm Wind | Denison | 1 hurt, $30,000 | A man was injured on the 1600 block of West Bond when a large tree fell through his home. He suffered minor cuts and bruises. |
| October 2014 | Lightning | Denison | 1 hurt | The Grayson County Emergency Manager reported a teacher at Lamar Elementary school was struck by lightning while walking to her car. |
| October 2014 | Lightning | Denison | 1 hurt | Lightning struck and injured a teacher about 15 minutes after school ended on Thursday. |
| May 2001 | Thunderstorm Wind | Denison | 1 hurt | A 70 year old woman was in critical condition after being struck in the head by a tree limb. The limb was blown down by high winds at a Denison Dam campground. |
| June 2007 | Flash Flood | Denison | $320,000 | Highway 69 east of Denison was flooded and closed, as was Highway 75 north of town. A few homes in Denison were flooded. Several bridges were washed out in Sherman including bridges on Mayes Road and Ida Road. An automotive shop in Denison had water damage to computers, furniture, and cars and expected damages to total around $250,000. |
| May 2011 | Thunderstorm Wind | Denison | $150,000 | A 65 MPH wind gust was measured in northern Denison. Throughout the city, numerous trees were uprooted, large limbs were knocked down, damage occurred to outbuildings, and minor damage to local businesses was reported. The awning of a gas station at Highway 75 and FM 120 was torn off. |
| April 2024 | Lightning | Denison | $100,000 | Emergency management reported a tank battery fire caused by a lightning strike near the intersection of FM 1417 and Davy Ln in Denison. |
| September 2023 | Flash Flood | Denison | $100,000 | Heavy rainfall in Denison caused water to flow into businesses in the downtown area. Multiple low-lying and poor drainage portions of roads were also closed in the area. |
| August 2009 | Thunderstorm Wind | Denison | $75,000 | Trees fell onto many homes in Denison, a parked truck and boat, and onto two carports. |
| March 2023 | Flood | Denison | $50,000 | Randell Lake Dr was washed out due to heavy rainfall that caused the creek to rise. |
| August 2002 | Thunderstorm Wind | Denison | $50,000 | A storage shed was destroyed when a tree was blown down on it, and a mobile home was destroyed when it was blown into another mobile home. There were numerous reports of trees blocking roads and streets. |
| April 2016 | Hail | Denison | $25,000 | Amateur radio spotters reported golf ball sized hail in the city of Denison. |
| May 2011 | Thunderstorm Wind | Denison | $25,000 | Thunderstorm winds knocked down trees and tree limbs in Denison. The steeple of the New Hope Christian Fellowship Church on South Mirick Avenue was blown off the roof. A tree at the church fell on the mail truck and telephone poles were snapped in the city. |
| April 2008 | Thunderstorm Wind | Denison | $20,000 | A brick building which was under construction partially collapsed in Denison. |
| March 2006 | Lightning | Denison | $20,000 | Lightning struck a radio antenna and ignited a fire in the attic of a Red Cross Building. Damage was mostly confined to the attic, where the fire destroyed wiring and electricity, as well as the roof of the building. Smoke and water damage also occurred inside the building. |
| May 1997 | Thunderstorm Wind | Denison | $20,000 | Strong winds destroyed an outdoor stage that was being used for a concert just a short time earlier. |
| May 2011 | Thunderstorm Wind | Denison | $15,000 | The 95-foot steeple of the Parkside Baptist Church was knocked over due to high winds. Other parts of the roof were also damaged. |
| February 2001 | Thunderstorm Wind | Denison | $15,000 | The roof of a medical center was damaged. Two nursing homes were also damaged. The reports came from the north part of town. |
| March 2006 | Thunderstorm Wind | Denison | $10,000 | Power lines down. |
| June 2001 | Thunderstorm Wind | Denison | $10,000 | Trees and power lines were blown down. The roof of a liquor store was partially destroyed. |
| April 1995 | Thunderstorm Wind | Denison | $10,000 | A storage building was destroyed by high winds. |
| June 2019 | Thunderstorm Wind | Denison | $8,000 | Emergency Management reported tree damage, light pole damage and window damage near Crawford and Armstrong Streets in the city of Denison, TX. |
| May 2015 | Thunderstorm Wind | Denison | $8,000 | Broadcast media reported roof and siding damage to homes and tree limbs down. One large tree limb fell on a home on Strawn Drive damaging the roof overhang over the garage and the garage door. |
| May 2025 | Thunderstorm Wind | Denison | $7,000 | Many Facebook reports relayed numerous trees down across Denison with widespread power outages. |
| May 2009 | Thunderstorm Wind | Denison | $7,000 | A large tree fell on a house in Denison. High winds also knocked down power lines. |
| April 2016 | Thunderstorm Wind | Denison | $6,000 | Thunderstorm winds damaged part of Denison High School and the school had to be closed the next day. |
| April 2015 | Flash Flood | Denison | $5,000 | A trained spotter reported 14-18 of water over the intersection of Morton Street at Maurice Ave in Denison. |
| June 2004 | Thunderstorm Wind | Denison | $5,000 | Utility poles were blown down by high winds. |
| August 2002 | Thunderstorm Wind | Denison | $5,000 | A metal awning was blown off a service station, and many streets were blocked from downed trees and limbs. |
| May 2009 | Thunderstorm Wind | Denison | $3,000 | An estimated 60 mph wind gust was reported in Denison. |
| June 2005 | Thunderstorm Wind | Denison | $3,000 | Power lines knocked down...relayed by broadcast media. |
| August 2002 | Thunderstorm Wind | Denison | $3,000 | Large trees were blown down by high winds. |
| June 2015 | Flash Flood | Denison | $2,000 | Several non-typical roadways were flooded in Denison including: 691 and Texoma Pkwy and Spur 503 and 91. Multiple roads in eastern portions of the county were flooded as well. |
| June 2004 | Thunderstorm Wind | Denison | $2,000 | Power lines were blown down by high winds. |
| April 1996 | Tornado (F0) | Denison | $2,000 | no account filed |
| February 2012 | Hail | Denison | $1,000 | Quarter sized hail was reported by amateur radio to be covering the ground 3 miles east of Denison. |
| February 2012 | Hail | Denison | $1,000 | A trained spotter reported quarter sized hail covering the ground 3 miles southwest of Denison making travel difficult. Hail fog was also occurring. |
| October 1994 | Thunderstorm Wind | Denison | $500 | Trees were blown down and two windows of an auto dealership were broken. |
| April 2026 | Hail | Denison | - | Emergency manager reported quarter sized hail 1 mile northwest of Downtown Denison. |
| April 2026 | Hail | Denison | - | Emergency manager reported quarter sized hail near Hwy 69 covering 5 percent of the ground. |
| March 2025 | Hail | Denison | - | Emergency manger reported quarter sized hail just southwest of Denison. |
| May 2025 | Hail | Denison | - | Report from mPING: Quarter (1.00 in.). |
| May 2025 | Hail | Denison | - | Report from mPING: Quarter (1.00 in.). |
| June 2025 | Hail | Denison | - | Report from mPING: Half Dollar (1.25 in.). |
| May 2024 | Flash Flood | Denison | - | Emergency management reported that several city streets in Denison were closed due to flooding. |
| April 2024 | Hail | Denison | - | Report from MPing. |
| November 2022 | Hail | Denison | - | A trained spotter reported brief quarter sized hail about 3 miles northwest of Denison, TX. |
| July 2020 | Thunderstorm Wind | Denison | - | A large tree was reported to be down in the road. Multiple trees were also reported to be down in West Denison. |
| September 2019 | Flood | Denison | - | Emergency management reported 4 to 6 inches of water on U.S. Highway 69 near the intersection of U.S. Highway 75 in the northern part of the city of Sherman, TX. |
| September 2019 | Flood | Denison | - | Emergency management reported that U.S. Highway 69 was being closed near the intersection of U.S. Highway 75 in the northern part of the city of Sherman, TX. |
| April 2018 | Hail | Denison | - | Amateur radio reported quarter sized hail at Eisenhower State Part, approximately 3 miles northwest of the city of Denison, TX. |
| April 2018 | Hail | Denison | - | Amateur radio reported quarter-sized hail at Denison Dam. |
| April 2018 | Hail | Denison | - | Emergency management reported half-dollar sized hail at Eisenhower State Park, or about 3 miles northwest of the city of Denison, TX. |
| July 2016 | Thunderstorm Wind | Denison | - | A social media report indicated wind gusts of 60 MPH in Denison, TX. |
| May 2015 | Flash Flood | Denison | - | Broadcast media reported that Pottsboro Road in Denison, TX was completely covered with water, and water was approaching a residential structure. |
| June 2012 | Hail | Denison | - | Dime sized hail was reported in Denison. |
| February 2012 | Hail | Denison | - | One inch diameter hail was reported by emergency management in Denison. |
| August 2012 | Thunderstorm Wind | Denison | - | A 60 mph wind gust was estimated in Denison. |
| August 2012 | Thunderstorm Wind | Denison | - | Sixty-two MPH winds were estimated near Downtown Denison. Large tree limbs were knocked down in the city; including Morgan Street. |
| May 2010 | Hail | Denison | - | Pea to nickel size hail fell in the city of Denison. |