Grayson County, Texas
Natural disaster risk, federal disaster history and flood insurance facts.
Grayson County, Texas has a relatively low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 80% of US counties. It ranks 52nd of 254 counties in Texas. The costliest hazards here are inland flooding, tornadoes and cold waves. FEMA estimates about $43 million a year in expected losses, or roughly $314 per resident. Since 1981 it has been included in 18 federal disaster or emergency declarations for natural events (11 major disasters). The most recent was in February 2021 (severe winter storms). Fewer than 1 in 100 homes here carry federal flood insurance (281 policies). Since 1978, federal flood insurance has paid about $18 million on 743 claims here, including $6.2 million for floods in 2007.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Grayson County
- Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
- Price a flood policy now. Most new federal policies take 30 days to start.
- Pick a shelter spot: a basement, or an inside room on the lowest floor with no windows.
- Turn on emergency alerts on your phone and keep a weather radio.
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Inland flooding | 79.5 | $19M | ||
| Tornado | 92.9 | $9M | ||
| Cold wave | 82.2 | $4M | ||
| Heat wave | 92.7 | $4M | ||
| Hail | 93.4 | $2M | ||
| Ice storm | 91.6 | $1M | ||
| Wildfire | 86.0 | $775K | ||
| Earthquake | 66.7 | $662K | ||
| Strong wind | 55.7 | $644K | ||
| Lightning | 56.2 | $291K | ||
| Drought | 47.7 | $125K | ||
| Hurricane | 53.3 | $103K | ||
| Winter weather | 57.0 | $82K | ||
| Landslide | 60.9 | $3K |
Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is relatively low and community resilience is relatively moderate in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included Grayson County. 2020s bar runs to November 2026.
By type
Most recent
Show all 18
Texas also had 106 statewide declarations that did not name single counties.
Storm history since 1952
Tornado risk by county ›The National Weather Service has logged 1,081 storm reports in Grayson County since 1952, with 11 deaths and 87 injuries and about $67.6 million in reported damage. The strongest on record here was an F3 tornado on April 6, 1955.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Apr 6, 1955 | F3 | – | 27 / 1 |
| May 9, 2006 | F3 | Pilot Grove | 4 / 1 |
| Apr 2, 1957 | F3 | – | 2 / 0 |
| Apr 18, 1957 | F3 | – | 0 / 0 |
| Mar 12, 1971 | F3 | – | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Jun 18, 2007 | Flash Flood | Collinsville | $20M |
| Apr 29, 1995 | Hail | – | $20M |
| Apr 6, 2003 | Hail | Sherman | $10M |
| Apr 6, 1955 | Tornado | – | $3M |
| Apr 29, 2009 | Flood | Lake Texhoma East | $2M |
| Dec 8, 2008 | Tornado | Denison Mckeon Arpt | $750K |
Source: NOAA Storm Events Database, county-based reports through May 10, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.
Hurricanes and tropical storms
Hurricane risk by county ›Since 1900, 0 hurricanes and 3 tropical storms have passed within 65 miles of the center of Grayson County, 1 of them since 1950. The strongest was an unnamed storm in 1900, with top winds near 50 mph about 65 miles away.
Strongest storms nearby
| Date | Storm | Strength | Closest |
|---|---|---|---|
| Sep 10, 1900 | Unnamed | Tropical storm, 50 mph | 65 mi |
| Sep 13, 1961 | Carla | Tropical storm, 40 mph | 51 mi |
| Jun 27, 1902 | Unnamed | Tropical storm, 40 mph | 57 mi |
Most recent storms
| Date | Storm | Strength | Closest |
|---|---|---|---|
| Sep 13, 1961 | Carla | Tropical storm, 40 mph | 51 mi |
| Jun 27, 1902 | Unnamed | Tropical storm, 40 mph | 57 mi |
| Sep 10, 1900 | Unnamed | Tropical storm, 50 mph | 65 mi |
Source: NOAA National Hurricane Center best-track records (HURDAT2), 1851 to 2025 for the Atlantic and 1949 to 2025 for the eastern Pacific. A storm counts if its track passed within 65 miles of the county's center while it was a tropical storm or hurricane. Strength is the storm's top sustained wind at that point, not the wind measured in the county. Older storms over the open sea were sometimes missed.
Flood insurance in Grayson County
Check your address flood zone ›National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.
Homes in Grayson County
Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 62,132 housing units.
Compare in Texas
All 254 ›| Largest counties | Overall risk | Top hazard |
|---|---|---|
| Harris County | Inland flooding | |
| Dallas County | Inland flooding | |
| Tarrant County | Inland flooding | |
| Bexar County | Inland flooding | |
| Travis County | Inland flooding | |
| Collin County | Tornado | |
| Denton County | Tornado | |
| Hidalgo County | Hurricane |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Collin County | 17 | |
| Denton County | 21 | |
| Bryan County, OK | 23 | |
| Cooke County | 20 | |
| Fannin County | 18 | |
| Marshall County, OK | 16 | |
| Love County, OK | 24 |
Cities in Grayson County
Common questions about Grayson County
What is the biggest natural hazard in Grayson County?
Inland flooding has the highest expected yearly losses in Grayson County, about $19 million a year in FEMA's estimate. Tornado is second at $9.2 million.
How many federal disasters has Grayson County had?
Grayson County has been included in 18 federal disaster or emergency declarations for natural events since 1981, including 11 major disasters. The most recent was Severe Winter Storms in February 2021.
Is Grayson County a high-risk place to live?
Its overall rating is Relatively Low, 52nd highest of 254 in Texas. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.
Do I need flood insurance in Grayson County?
Standard home insurance does not cover flooding. About 1 in 200 homes in Grayson County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.
How many tornadoes has Grayson County had?
NOAA records list 72 tornadoes in Grayson County since 1950. The strongest was an F3 tornado on April 6, 1955. The weather service has also logged 486 hail reports and 118 floods here.
How many hurricanes have hit Grayson County?
NOAA's hurricane records show 0 hurricanes and 3 tropical storms passing within 65 miles of the center of Grayson County. The strongest was an unnamed storm in 1900, with winds near 50 mph.
Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.