Grayson County, TX Environment & Hazard Risk

• HailRelatively Moderate$2.3M/yr expected annual loss, about 8.5 events a year
• TornadoRelatively High$9.2M/yr expected annual loss, about once every 1 year
• Heat waveRelatively Moderate$4M/yr expected annual loss, about 16 events a year
• Ice stormRelatively High$1.1M/yr expected annual loss, about 1.2 events a year
• WildfireRelatively Low$775K/yr expected annual loss, about once every 666 years
• Cold waveRelatively Moderate$4.2M/yr expected annual loss, about 1.1 events a year
• EarthquakeRelatively Low$662K/yr expected annual loss, about once every 864 years
• LandslideVery Low$2,806/yr expected annual loss, about once every 5 years
• Winter weatherRelatively Low$82.3K/yr expected annual loss, about 4.9 events a year
• LightningRelatively Low$291K/yr expected annual loss, about 55 events a year
• Strong windRelatively Moderate$644K/yr expected annual loss, about 4.0 events a year
• HurricaneVery Low$103K/yr expected annual loss, about once every 96 years
• DroughtRelatively Low$125K/yr expected annual loss, about 28 events a year

Bars show the national percentile score (0 to 100) for each hazard. Dollar figures are expected annual losses to buildings, people and crops. Not rated here: avalanche, coastal flooding, riverine flooding, tsunami, volcanic activity.

Check the flood zone for an address

Homes with flood insurance

281 of 57,645 (0.5%)

Homes in high-risk flood zones

905

Insured in high-risk zones

153 (17%)

Flood claims since 1978

743

Claims paid since 1978

$18.3M

• Hail369
• Thunderstorm Wind264 · 1 death
• Flash Flood98 · 3 deaths
• Drought76
• Heat41
• Winter Storm21
• Tornado21 · 2 deaths
• Flood20 · 2 deaths
• Winter Weather18 · 2 deaths
• Excessive Heat15

• Winter Storm12/05/2013

  Grayson

  36 injured, $7M damage

  What happened

  Up to 4 of ice and sleet accumulated in Grayson County. On average, 3-4 of ice and sleet was reported and most of the reports were sleet accumulations. One media station in Denison reported 0.10 ice with 3 of sleet accumulations. Traffic became very difficult, including Highway 82 and Highway 289. Several traffic accidents occurred on the icy streets and hundreds of tree branches broke due to the weight of the ice. Due to the weight of the ice, the Lonestar Lanes Bowling Alley in Sherman collapsed on the 6th and the gymnasium roof at the Boys and Girls Club in Sherman also caved in. The roof of the Cooper-B building sagged inward due to the ice. In Denison, an awning collapsed at the Main Street Lumber, and several porch covers on house also collapsed. Tom Bean ISD reported minor damage to some of their buildings including roof leaks at the elementary school and a portion of the high school roof was sagging, plus a shed in the bus barn was crushed by the weight of the ice. Power lines were also knocked down by the ice resulting in many power outages. Sherman police reported 6 vehicle accidents with injuries and the Texoma Medical Center reported approximately 30 injuries due to...

• Flash Flood06/18/2007

  Collinsville, Grayson County

  2 deaths, $20M damage

  What happened

  Significant flooding occurred with cars and mobile homes moved by the force of the water. Numerous roads were closed across the county, including Highways 377 and 75, and more than 450 people were rescued from high water. One woman died in floodwaters as she drove on Texoma Parkway under the U.S. Highway 75 overpass. Another fatality occurred when a truck flooded at the intersection of FM 1417 and Highway 11. A bridge on Highway 11 south of Sherman suffered extensive damage.

• TornadoEF2, 2.38 mi path, 150 yd wide03/22/2022

  Cedar Mills, Grayson County

  1 death, 11 injured

  What happened

  The tornado first touched down in a field near Thousand Oak Trails. It then moved through the Sherwood Oaks community, producing extensive and widespread damage to trees and homes. Multiple manufactured homes were flipped, many trees were snapped in half, and one home was moved off its foundation. The tornado then crossed Lake Texoma and moved into Marshall County Oklahoma. A total of 105 structures were damaged, 53 destroyed, and 27 sustained major damage. Maximum estimated winds in Grayson County were 130 mph. One fatality occurred in a mobile home.

• Flood12/24/2024

  Sherman Muni Arpt, Grayson County

  2 deaths, $50K damage

  What happened

  Two fatalities occurred when their SUV hydroplaned off of the US 75 service road and ended up overturned in a flooded drainage culvert. The two individuals were swept away into Post Oak Creek.

• Thunderstorm Wind43 kt wind06/27/2024

  Cedar Mills, Grayson County

  1 death, 7 injured

  What happened

  A boat with 8 people on board capsized in thunderstorm winds resulting in the fatality of a 6 year old boy.

• Winter Weather12/16/2008

  Grayson

  15 injured

  What happened

  A total of 94 accidents occurred in Sherman, Denison, Howe, and Van Alstyne due to icy conditions. More than 10 of the wrecks resulted in injuries which required hospital treatment. Numerous other cars skidded into ditches. Most of the accidents occurred on Highways 75 and 82.

• City of ShermanServes 43,645 · Surface water · Local governmentNo health violations+6 monitoring or reporting
• City of DenisonServes 27,500 · Surface water · Local governmentNo health violations+3 monitoring or reporting
• City of Van AlstyneServes 10,644 · Purchased surface water · Local governmentNo health violations+13 monitoring or reporting
• Two Way SudServes 6,804 · Groundwater · Local governmentNo health violations
• South Grayson SudServes 6,750 · Groundwater · Local governmentNo health violations+3 monitoring or reporting
• City of HoweServes 4,548 · Purchased surface water · Local governmentNo health violations+18 monitoring or reporting
• Kentuckytown WscServes 4,455 · Groundwater · Local governmentNo health violations+2 monitoring or reporting
• Tanglewood on TexomaServes 4,341 · Purchased surface water · PrivateNo health violations