Denison, Texas: natural disaster risk
How exposed Denison is to floods, storms and other hazards, from FEMA and NOAA records for Grayson County.
Denison is a city of 25,778 people in Grayson County, Texas. FEMA's National Risk Index rates Grayson County relatively low for natural hazards overall, lower than most of the US. The costliest hazards there are inland flooding, tornado and cold wave, with about $42.6 million in expected losses a year across the county. The weather service has logged 1,081 storm reports in the county since 1952, including 72 tornadoes and 118 floods. NOAA hurricane records show 0 hurricanes and 3 tropical storms passing within 65 miles of the county's center. About 0.5% of homes in the county carry federal flood insurance.
Risk figures are for Grayson County. FEMA National Risk Index December 2025; NOAA Storm Events; US Census Bureau ACS 2020 to 2024. Updated November 6, 2026.
Top risks in Denison
Full Grayson County report ›- 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 hazards
| Hazard | Rating | A year |
|---|---|---|
| Inland flooding | $19M | |
| Tornado | $9M | |
| Cold wave | $4M | |
| Heat wave | $4M | |
| Hail | $2M | |
| Ice storm | $1M | |
| Wildfire | $775K | |
| Earthquake | $662K | |
| Strong wind | $644K | |
| Lightning | $291K | |
| Drought | $125K | |
| Hurricane | $103K |
Homes in Denison
Older homes and mobile homes usually take more damage in storms, floods and earthquakes. Ask about roof age, flood history and retrofits before you buy or rent.
Strongest tornadoes in Grayson County
More cities in Grayson County
Common questions about Denison
Is Denison safe from natural disasters?
Denison is in Grayson County, which FEMA's National Risk Index rates relatively low overall, lower than most of the US. The biggest hazards are inland flooding, tornado, cold wave. No place is free of risk, so check the flood map and insurance for any home you consider.
What natural disasters happen in Denison?
By expected yearly losses in Grayson County, the top hazards are inland flooding (Moderate), tornado (High), cold wave (Moderate). Grayson County has been part of 18 federal disaster or emergency declarations for natural events.
Does Denison get tornadoes?
Yes. NOAA records list 72 tornadoes in Grayson County since 1950; the strongest was an F3 tornado on April 6, 1955. FEMA rates tornado risk in the county high.
Do I need flood insurance in Denison?
Standard home insurance does not cover floods. In Grayson County, about 0.5% of homes have federal flood insurance, and FEMA rates inland flooding risk moderate. Check the FEMA flood map for your address and get a quote even outside a high-risk zone.