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Natural hazard risk in Grayson County, Texas

Updated October 30, 2026. Based on FEMA, NOAA and OpenFEMA data. Published by Humblebee.

FEMA overall Risk Index rating: Relatively Low (score 80.3 of 100)[5]

Expected annual loss (FEMA)
$42.6 million[1]
Federal disaster declarations since 1981
18[2]
NFIP flood claims paid, 1978 to 2026
$18.3 million[3]
Tornadoes recorded, 1950 to 2024
70[4]

FEMA's National Risk Index rates Grayson County's overall natural hazard risk Relatively Low compared with other US counties, with a score of 80.3 out of 100[5]. The hazards with the highest FEMA scores within the county are hail, tornado and heat wave[6].

FEMA risk ratings for each hazard

Ratings and expected losses from the FEMA National Risk Index. Each rating compares this county with all US counties for that hazard, from Very Low to Very High. They are planning estimates, not predictions, and they do not describe any single property.

FEMA's National Risk Index estimates Expected Annual Loss from all 18 natural hazards at $42.6 million a year[1]. This is FEMA's estimate of average yearly loss, not money anyone paid[7]. The largest hazard-type values are inland flooding at $19.0 million a year, tornado at $9.2 million a year and cold wave at $4.2 million a year[8]. FEMA rates Social Vulnerability Relatively Low (score 38.7)[9]. FEMA rates Community Resilience Relatively Moderate (score 44.2)[10]. The index does not predict next year's losses[7].

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
HailRelatively Moderate$2.3 million[11]
TornadoRelatively High$9.2 million[12]
Heat WaveRelatively Moderate$4.0 million[13]
Ice StormRelatively High$1.1 million[14]
WildfireRelatively Low$775,000[15]
Cold WaveRelatively Moderate$4.2 million[16]
Inland FloodingRelatively Moderate$19.0 million[17]
EarthquakeRelatively Low$662,000[18]
LandslideVery Low$2,806[19]
Winter WeatherRelatively Low$82,000[20]
LightningRelatively Low$291,000[21]
Strong WindRelatively Moderate$644,000[22]
HurricaneVery Low$103,000[23]
DroughtRelatively Low$125,000[24]

Rated Not Applicable by FEMA for this county: avalanche, coastal flooding, tsunami, volcanic activity[25].

Social vulnerability and community resilience

FEMA uses these two ratings to scale expected losses into the Risk Index.

FEMA measureRatingScore
Social vulnerabilityRelatively Low38.7[9]
Community resilienceRelatively Moderate44.2[10]

Flooding and flood insurance

FEMA rates inland flooding risk Relatively Moderate for Grayson County compared with other US counties[17]. OpenFEMA lists 281 residential flood insurance contracts in force, a penetration rate of 0.5% as of 2026-08-03[26]. Inside FEMA's mapped Special Flood Hazard Area, 16.9% of homes are insured[26]. OpenFEMA records 743 NFIP claims for losses from 1978 to 2026, and NFIP paid $18.3 million in total[3]. To check a specific address, use FEMA's Flood Map Service Center[27].

Measure Value
Inland Flooding, FEMA risk rating[17] Relatively Moderate, $19.0 million expected loss a year
NFIP residential flood policies in force (2026)[26] 281 of 57,645 homes
Homes in FEMA's mapped high-risk flood area (SFHA)[26] 905, of which 153 insured
NFIP flood claims, 1978 to 2026[3] 743 filed, $18.3 million paid

Is a specific address in a flood zone? Only FEMA's flood maps answer that, property by property[27]. This page describes the whole county.

Search an address on the FEMA Flood Map Service Center

Disaster declarations and tornado records

OpenFEMA lists 18 federal disaster declarations for natural hazards that include Grayson County since 1981[2]. The most recent is DR-4586-TX for Severe Winter Storms, declared 2021-02-19[28]. NOAA's tornado database records 70 tornadoes that touched the county from 1950 to 2024[4]. The most recent recorded tornado was on 2016-04-26[4].

Federal disaster declarations for natural hazards that include Grayson County, since 1981
Incident type Declarations
Severe Storm[2] 5
Hurricane[2] 4
Fire[2] 4
Severe Ice Storm[2] 3
Drought[2] 1
Flood[2] 1
Most recent declarations
Declaration Incident Declared
DR-4586-TX[28] Severe Winter Storms 2021-02-19
EM-3554-TX[28] Severe Winter Storm 2021-02-14
DR-4223-TX[28] Severe Storms, Tornadoes, Straight-Line Winds And Flooding 2015-05-29
DR-4029-TX[28] Wildfires 2011-09-09
EM-3294-TX[28] Hurricane Ike 2008-09-10

How to prepare

Steps from Ready.gov, FEMA's preparedness site, for the hazards with the highest FEMA ratings here. Follow instructions from local officials and the National Weather Service when a warning is issued.

Tornadoes

Before

  • Learn the warning signs: a rotating funnel cloud, an approaching cloud of debris or a loud roar like a freight train.
  • Sign up for community warning systems and learn what your local sirens sound like.
  • Pick a safe spot, such as a safe room built to FEMA criteria or an ICC 500 storm shelter, and practice getting there.
  • Include your pets in the household emergency plan.
  • Keep supplies, food, water and medication in case you have to stay home for a long time.

During

  • Go right away to the safe place you picked in advance.
  • Protect your head and neck with your arms and stay away from windows, doors and outside walls.
  • No place in a car is fully safe. If you can get lower than the road, leave the car and lie down there.

Source: Ready.gov, tornadoes

Extreme heat

Before

  • Learn the signs of heat illness and how to respond.
  • Do not rely on a fan as your main way to stay cool. Fans do not lower body temperature.
  • Find cool public places, such as libraries or malls, or ask your local health department.
  • Keep heat out with window shades, weather stripping and insulation.
  • If you cannot afford cooling costs, contact LIHEAP for help.

During

  • Never leave a person or an animal in a parked car in warm weather.
  • If your home has no air conditioning, go to a cooling center.
  • Wear light, loose clothing, drink plenty of fluids and avoid hard outdoor work in the middle of the day.

Source: Ready.gov, extreme heat

Winter storms and cold

Before

  • Insulate your home and learn how to keep pipes from freezing.
  • Install and test smoke and carbon monoxide detectors with battery backup.
  • Keep several days of supplies in case the power goes out, including medication and pet needs.
  • Put an emergency kit in your car with jumper cables, sand, blankets, water and snacks, and keep the tank full.

During

  • Under a winter storm warning, find shelter right away.
  • Stay off the roads if you can. If you are stuck in your car, stay inside it.
  • Run generators and grills only outdoors, away from windows, and never heat your home with an oven or stove.

Source: Ready.gov, winter storms and cold

Questions people ask

Is Grayson County at risk of flooding?
FEMA rates inland flooding risk Relatively Moderate compared with other US counties[17]. FEMA's Flood Map Service Center shows the flood zone for a specific address[27].
Does Grayson County get tornadoes?
FEMA rates tornado risk Relatively High compared with other US counties[12]. NOAA's tornado database records 70 tornadoes touching the county from 1950 to 2024[4].
Is Grayson County at risk of earthquakes?
FEMA rates earthquake risk Relatively Low compared with other US counties[18].
How many disasters have been declared in Grayson County?
OpenFEMA lists 18 federal disaster declarations for natural hazards that include the county since 1981[2].
How do I check my flood zone?
Look up the address in FEMA's Flood Map Service Center or ask the local floodplain manager[27].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in Grayson County is $42.6 million a year (Expected Annual Loss rating Relatively Low, score 81.0). Of this, buildings account for $23.8 million, injuries and deaths (converted to dollars by FEMA) for $18.5... FEMA National Risk Index
  2. OpenFEMA Disaster Declarations Summaries list 18 federal disaster declarations for natural hazards that include Grayson County since 1981 (11 major disaster, 7 emergency or fire management). By incident type: severe storm 5, hurricane 4, fire 4, severe ice storm 3, drought 1, flood 1. Biological (such as COVID-19)... OpenFEMA Disaster Declarations
  3. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 743 National Flood Insurance Program claims were filed for losses in Grayson County, 614 of them with a payment, and NFIP paid $18.3 million in total (building, contents and increased cost of compliance, in dollars of the year paid).... OpenFEMA NFIP claims
  4. NOAA Storm Prediction Center tornado database (1950 to 2024): 70 recorded tornadoes touched Grayson County. The strongest were rated F3 (most recent of them on 2006-05-09). 9 were rated F3/EF3 or stronger. The most recent recorded tornado was on 2016-04-26. Ratings used the Fujita scale until early 2007 and the... NOAA Storm Prediction Center
  5. FEMA National Risk Index (version 1.20, December 2025): the overall natural hazard Risk Index rating for Grayson County is Relatively Low, with a Risk Index score of 80.3 out of 100. The score is the county's percentile rank among all US counties. FEMA National Risk Index
  6. Among the 18 hazards in the FEMA National Risk Index (version 1.20, December 2025), the hazards with the highest hazard-type Risk Index scores for Grayson County are hail (93.4, Relatively Moderate), tornado (92.8, Relatively High), heat wave (92.7, Relatively Moderate). HazardFacts sorted FEMA's published scores;... FEMA National Risk Index
  7. FEMA's National Risk Index FAQ (December 2025): Expected Annual Loss is FEMA's estimate of the average economic loss in dollars from natural hazards each year. The index is not meant to predict how much damage a community will have in the next year, and a hazard can still cause damage where a rating is low. Scores... FEMA National Risk Index documentation
  8. HazardFacts sorted FEMA's hazard-type Expected Annual Loss values for Grayson County (National Risk Index v1.20): the largest are inland flooding ($19.0 million a year), tornado ($9.2 million a year), cold wave ($4.2 million a year), out of $42.6 million a year from all 18 hazards. FEMA National Risk Index
  9. FEMA National Risk Index (version 1.20, December 2025): Social Vulnerability rating for Grayson County is Relatively Low (score 38.7). FEMA describes social vulnerability as how susceptible social groups are to the harm natural hazards cause. FEMA National Risk Index
  10. FEMA National Risk Index (version 1.20, December 2025): Community Resilience rating for Grayson County is Relatively Moderate (score 44.2). FEMA describes community resilience as a community's ability to prepare for, withstand and recover from hazards. FEMA National Risk Index
  11. FEMA National Risk Index (version 1.20, December 2025), hail in Grayson County: Risk Index rating Relatively Moderate (score 93.4 of 100). Expected Annual Loss $2.3 million a year (rating Relatively Moderate). Annualized frequency 8.54 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  12. FEMA National Risk Index (version 1.20, December 2025), tornado in Grayson County: Risk Index rating Relatively High (score 92.8 of 100). Expected Annual Loss $9.2 million a year (rating Relatively High). Annualized frequency 0.88 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), heat wave in Grayson County: Risk Index rating Relatively Moderate (score 92.7 of 100). Expected Annual Loss $4.0 million a year (rating Relatively Moderate). Annualized frequency 15.95 event-days per year, from recorded occurrences over a period of record of... FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), ice storm in Grayson County: Risk Index rating Relatively High (score 91.6 of 100). Expected Annual Loss $1.1 million a year (rating Relatively High). Annualized frequency 1.25 event-days per year, from recorded occurrences over a period of record of 68 years. FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), wildfire in Grayson County: Risk Index rating Relatively Low (score 86.0 of 100). Expected Annual Loss $775,000 a year (rating Relatively Low). FEMA's modeled annual frequency is 0.0015 events per year. FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025), cold wave in Grayson County: Risk Index rating Relatively Moderate (score 82.2 of 100). Expected Annual Loss $4.2 million a year (rating Relatively High). Annualized frequency 1.05 event-days per year, from recorded occurrences over a period of record of 18... FEMA National Risk Index
  17. FEMA National Risk Index (version 1.20, December 2025), inland flooding in Grayson County: Risk Index rating Relatively Moderate (score 79.5 of 100). Expected Annual Loss $19.0 million a year (rating Relatively Moderate). Annualized frequency 2.18 event-days per year, from recorded occurrences over a period of... FEMA National Risk Index
  18. FEMA National Risk Index (version 1.20, December 2025), earthquake in Grayson County: Risk Index rating Relatively Low (score 66.6 of 100). Expected Annual Loss $662,000 a year (rating Relatively Low). FEMA's modeled annual frequency is 0.0012 events per year. FEMA National Risk Index
  19. FEMA National Risk Index (version 1.20, December 2025), landslide in Grayson County: Risk Index rating Very Low (score 60.8 of 100). Expected Annual Loss $2,806 a year (rating Very Low). FEMA National Risk Index
  20. FEMA National Risk Index (version 1.20, December 2025), winter weather in Grayson County: Risk Index rating Relatively Low (score 57.0 of 100). Expected Annual Loss $82,000 a year (rating Relatively Moderate). Annualized frequency 4.95 events per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  21. FEMA National Risk Index (version 1.20, December 2025), lightning in Grayson County: Risk Index rating Relatively Low (score 56.1 of 100). Expected Annual Loss $291,000 a year (rating Relatively Low). Annualized frequency 54.88 events per year, from recorded occurrences over a period of record of 24 years. FEMA National Risk Index
  22. FEMA National Risk Index (version 1.20, December 2025), strong wind in Grayson County: Risk Index rating Relatively Moderate (score 55.7 of 100). Expected Annual Loss $644,000 a year (rating Relatively Moderate). Annualized frequency 3.99 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  23. FEMA National Risk Index (version 1.20, December 2025), hurricane in Grayson County: Risk Index rating Very Low (score 53.3 of 100). Expected Annual Loss $103,000 a year (rating Very Low). Annualized frequency 0.01 events per year, from recorded occurrences over a period of record of 172 years for the Atlantic... FEMA National Risk Index
  24. FEMA National Risk Index (version 1.20, December 2025), drought in Grayson County: Risk Index rating Relatively Low (score 47.7 of 100). Expected Annual Loss $125,000 a year (rating Relatively Low). Annualized frequency 28.1 event-days per year, from recorded occurrences over a period of record of 22 years. FEMA National Risk Index
  25. FEMA National Risk Index (version 1.20, December 2025) rates these hazards Not Applicable for Grayson County: avalanche, coastal flooding, tsunami, volcanic activity. FEMA uses Not Applicable when its source data has no historical record of the hazard in the community and the hazard is not considered geographically... FEMA National Risk Index documentation
  26. NFIP Residential Penetration Rates (OpenFEMA, as of 2026-08-03): 281 residential flood insurance contracts were in force in Grayson County, out of 57,645 residential structures, a penetration rate of 0.5%. Inside FEMA's mapped Special Flood Hazard Area there were 905 residential structures and 153 contracts, a rate... OpenFEMA NFIP penetration rates
  27. FEMA's Flood Map Service Center is the official public source for flood maps (Flood Insurance Rate Maps) produced under the National Flood Insurance Program. Flood zones apply to specific properties: look up an address there or ask the local floodplain manager. County-level ratings do not tell you the flood zone of... FEMA Flood Map Service Center
  28. Most recent federal disaster declarations for natural hazards (table on this page). OpenFEMA Disaster Declarations

FEMA's National Risk Index compares each county with all other US counties. Ratings are relative (Very Low to Very High), not a measure of safety. Never call a place safe, unsafe, good or bad to live in. Risk Index and Expected Annual Loss values are FEMA estimates for planning. They do not predict next year's losses and do not apply to a single property. Flood zones are set by FEMA flood maps for specific properties. County ratings and flood insurance counts do not tell anyone whether an address is in a flood zone. Disaster declaration, NFIP and tornado counts are records of the past for this county only. Do not compare with other counties unless a fact does.

Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties, v1.20 (December 2025). Retrieved from fema.maps.arcgis.com on October 30, 2026. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets 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). This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.