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Grayson County, Texas Flood Zones

Check an Address in Grayson County

Enter any address in Grayson County, Texas to see its FEMA flood zone

The Flooding Character of Grayson County

Flash flooding from thunderstorms is the primary flood hazard in Grayson County. Recent events include widespread showers and thunderstorms producing flash flooding on April 30, 2025, and substantial rainfall leading to flash flooding on August 30, 2025.

National Flood Insurance Program data indicates that properties in Zone A have experienced the most claims, with an average payout of $24,021 and an average water depth of 3.5 feet. Properties in Zone X, while fewer in number, have seen higher average payouts ($31,727) and deeper water on average (5.5 feet). Homeowners in Zone A and Zone X, as well as those in areas with unknown flood zone designations, should pay particular attention to flood risk.

Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.

Read First-Hand Flood Stories from Grayson County

31 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.

Read Texas flood stories →

Flood Risk Data for Grayson County

Grayson County, Texas has recorded 118 flood-related events since 1996 according to NOAA's Storm Events Database, including 97 flash floods and 20 river or area floods. The county has received 21 federal disaster declarations, 1 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.

Grayson County Disaster History

FEMA Disaster Declarations (1981–2021)

Disaster Declarations
21
Flood/Coastal Disasters
1
Hurricane Disasters
1
Latest Disaster
Severe Winter Storms (2021-02-11)

Source: OpenFEMA Disaster Declarations Summaries.

Recent Disaster Declarations in Grayson County

DeclarationTypeDate
Severe Winter StormSevere Ice StormFeb 11, 2021
Severe Winter StormsSevere Ice StormFeb 11, 2021
Covid-19BiologicalJan 20, 2020
Covid-19 PandemicBiologicalJan 20, 2020
Severe Storms, Tornadoes, Straight-line Winds And FloodingSevere StormMay 4, 2015
WildfiresFireAug 30, 2011
Hurricane IkeHurricaneSep 7, 2008
WildfiresFireMar 14, 2008
Severe Storms, Tornadoes, And FloodingSevere StormJun 16, 2007
Extreme Wildfire ThreatFireNov 27, 2005

Recorded Flood Events in Grayson County

NOAA Storm Events Database (1996–2025)

Total Flood Events
118
River/Area Floods
20
Flash Floods
97
Hurricanes/Tropical Storms
1
Total Property Damage
$24.5M
Flood Deaths
5
Flood Injuries
1

Source: NOAA National Weather Service Storm Events Database.

Recent Flood Events in Grayson County

TypeDateDamage
FloodAug 30, 20251.00K
Flash FloodApr 30, 20250.00K
Flash FloodMay 25, 20240.00K
FloodDec 24, 202450.00K (2 deaths)
Flash FloodMay 23, 20240.00K
Flash FloodJul 23, 20242.00K
Flash FloodJul 23, 20241.00K
Flash FloodMay 22, 20240.00K
Flash FloodMay 12, 202418.00K
Flash FloodMay 12, 20240.00K

Grayson County Flood History

Flood — Aug 30, 2025

A slow-moving summer frontal system, in conjunction with occasional disturbances embedded within the northwest flow aloft, generated multiple rounds of thunderstorms both preceding and during the Labor Day weekend. The predominant hazard observed was flash flooding, attributed to the substantial rainfall produced by some of these storms.

Flash Flood — Apr 30, 2025

A slow moving front and an upper trough generated scattered thunderstorms on April 29, and widespread showers and thunderstorms on April 30, across much of North and Central Texas. Some of these storms became severe with large hail and damaging winds, but the most impactful weather was flash flooding due to the slow movement of the front and the resulting ���training��� of thunderst...

Flash Flood — May 25, 2024

Another round of dryline-induced convection took place the night of May 25 as a shortwave trough moved overhead. Thunderstorms were more isolated in nature, but one ambitious supercell produced multiple tornadoes the evening of May 25th. A total of 5 tornadoes were produced by the supercell as it moved across Montague, Cooke, Denton, Collin, and Hunt counties, and one more EF-2 occurred from a ...

Flood — Dec 24, 2024

Thunderstorms developed along a Pacific cold front as it and an upper level trough swept through the Plains on Christmas Eve 2024. The system produce a few severe storms across Central Texas and flash flooding in parts of North Texas. In addition, a brief EF-0 occurred in southwest Freestone County damaging 2 properties.

Flash Flood — May 23, 2024

With a highly unstable airmass in place, a meandering front, a dryline, and a shortwave trough all worked together to generate multiple rounds of thunderstorms May 23 and 24. In addition to large hail and damaging winds, multiple tornadoes also occurred along with a few instances of flash flooding. A total of 6 tornadoes occurred in Central and East Texas: 2 EF-1s, 3 EF-0s, and 1 EF-U.

Source: NOAA National Weather Service Storm Events Database.

Grayson County NFIP Flood Insurance Claims

Total Claims Filed
624
Total Paid Out
$14.9M
Avg Claim
$28,408
Avg Water Depth
5.4 ft

Claims by Flood Zone

A Zones (High Risk)
409
X Shaded (500-yr)
11
X Unshaded (Low)
43

Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).

Flood Zone Types in Grayson County

FEMA assigns flood zone designations to areas in Grayson County, Texas:

AE High Risk — 1% annual chance of flooding. Insurance required.

VE Very High Risk — Coastal flooding with wave action.

X (Shaded) Moderate Risk — 500-year floodplain.

X Low Risk — Outside major floodplains.

View all flood zone types →

Flood Insurance in Grayson County

Properties in Grayson County, Texas that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.

Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.

Visit FloodSmart.gov to find an agent and get a quote.