743 flood insurance claims·$18.2M paid·2 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Grayson County, Texas. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
Flash flooding from slow-moving thunderstorms and frontal systems dominates the flood character of Grayson County, Texas, accounting for 97 flash flood events and 3 deaths over the last 30 years, alongside 20 standard flood events causing 2 deaths and 1 tropical depression.
Recent NOAA storm data illustrates these recurring hazards. On May 22, 2024, a cold front and strong jet stream produced widespread thunderstorms, resulting in damaging winds, large hail, and flash flooding. Another significant event occurred on April 30, 2025, when a slow-moving front and upper trough generated widespread showers and training thunderstorms that caused impactful flash flooding across the region.
NFIP insurance claims data indicates that property owners in both designated high-risk and moderate-to-low-risk areas experience significant flooding. Zone A leads the county with 480 claims, averaging a $27,960 payout and an average recorded water depth of 5 inches. Meanwhile, Zone X properties recorded 156 claims with a higher average payout of $45,530 and an average recorded water depth of 9 inches. Homeowners in both Zone A and Zone X, as well as properties in lesser-impacted zones such as Zone X unshaded, Zone X shaded, and unknown zones, should pay the closest attention to local flood risks given the documented payouts and water depths.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
12% of Grayson County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
544 NFIP claims with a recorded rated flood zone, 1978 to date. The zone is the one FEMA used to rate that policy, which may not match today’s map. Source: OpenFEMA NFIP claims.
In flood insurance claims here that reported a flood depth, the average was 5 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 1986, with 152 claims and $1.2M paid.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
31 NOAA storm reports from Grayson County describe what happened, in the words of the forecasters who covered it. Read the Texas flood stories →
21 federal disaster declarations since 1981, 2 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Winter Storm | Feb 11, 2021 |
| Severe Winter Storms | Feb 11, 2021 |
| Severe Storms, Tornadoes, Straight-line Winds And Flooding | May 4, 2015 |
| Wildfires | Aug 30, 2011 |
| Hurricane Ike | Sep 7, 2008 |
| Wildfires | Mar 14, 2008 |
| Severe Storms, Tornadoes, And Flooding | Jun 16, 2007 |
| Extreme Wildfire Threat | Nov 27, 2005 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
118 since 1996: 97 flash floods and 20 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flood | Aug 30, 2025 | $1,000 |
| Flash Flood | Apr 30, 2025 | — |
| Flash Flood | May 25, 2024 | — |
| Flood | Dec 24, 2024 | $50,000 · 2 killed |
| Flash Flood | May 23, 2024 | — |
| Flash Flood | Jul 23, 2024 | $2,000 |
| Flash Flood | Jul 23, 2024 | $1,000 |
| Flash Flood | May 22, 2024 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
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 thunderstorms along and near…
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 separate storm in Ea…
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.
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Grayson County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.