Key facts: Houston
- Houston has flat ground, clay soil and slow bayous, and Hurricane Harvey dropped more than 60 inches of rain in parts of southeast Texas in 2017.[1]
- Allison in 2001 and Harvey in 2017 both showed that Houston floods from rain alone, well away from the coast.[1][2]
- The February 2021 freeze split lines across the region, and the leaks often showed only on the thaw.[3]
Rain-made floods
Freezes on Gulf Coast plumbing
Pipes here often run through attics. The February 2021 freeze split lines across the region, and the leaks often showed only on the thaw.[3]
Flood claims recorded in Harris County
Houston sits in Harris County. FEMA publishes every National Flood Insurance Program claim with personal details removed, which gives a plain record of where water has reached insured buildings here.
| Measure | Count |
|---|---|
| Flood insurance claims on record | 170,854 |
| Year with the most claims | 2017 (49,788) |
| Largest named event | Hurricane Harvey (48,992) |
| Claims outside high-risk A and V zones | 55% |
| Claims on buildings built before 1975 | 57% |
County-wide counts of insured claims only. Uninsured losses, burst pipes and appliance leaks are not in this data.
What the Houston claim record shows
For Houston homes, the local precedents are the events behind the most Harris County claims: Hurricane Harvey (48,992 claims), Tropical Storm Allison (25,050 claims) and Flooding (22,506 claims).
About 55% of claims with a recorded zone came from outside the high-risk A and V zones, so a moderate-risk label does not mean a Houston home stays dry.
If your Houston home is older, note that buildings from before 1975 make up 57% of county claims with a known build date. Many predate current flood maps, so inspect low outlets, ductwork and subfloors closely after any water event.
Federal disaster history for Harris County
FEMA lists 41 federal declarations covering Harris County. The most common types are hurricane (12), flood (12) and severe storm (8). The latest are Hurricane Beryl in 2024, Severe Storms, Straight-Line Winds, Tornadoes, and Flooding in 2024 and Severe Winter Storms in 2021. If your loss falls inside an open declaration, Houston homeowners can check DisasterAssistance.gov as well as their insurance policy.
Houston weather and your home
Weather records for Houston from 2015 through 2024 average 75 inches of precipitation a year, and May and September are the wettest months. The area averages 20.6 days a year with an inch or more.
Freezing nights are rare, at about 5 a year in Houston, so the bigger concerns are storms, plumbing failures and humidity.
With about 61 days a year at 90°F or hotter, Houston air conditioners run hard, and a clogged condensate line can soak a ceiling without warning.
At 21 heavy-rain days a year, clear gutters matter in Houston, and doors and low windows are worth watching.
When rain falls in Houston
Seasonal averages for Houston, 2015 through 2024. Plan roof, gutter and sump pump checks before the wettest stretch.
| Season | Average | Share of year |
|---|---|---|
| January to March | 14.9 in | 20% |
| April to June | 22.8 in | 30% |
| July to September | 21.7 in | 29% |
| October to December | 16.0 in | 21% |
Modeled from Open-Meteo historical weather data. Precipitation includes rain and melted snow.
Houston home checklist from these records
- Treat flood risk as current. 43% of Harris County claims date from 2015 or later.
- Test any sump pump before May, since Houston averages 21 days a year with an inch or more.
- Clear the air conditioner drain line before the 61 days of 90°F heat begin.
- Keep dated photos of each room. After Hurricane Harvey, 48,992 insured Harris County owners filed claims at about the same time.
What to tell the Houston contractor
- Your nearest bayou
- Whether the home flooded before
- Whether the leak is in the attic
Services Houston callers ask about
Questions
Houston water damage questions
Do I need flood insurance outside a flood zone?
It's worth considering, since many Harvey losses were outside mapped zones.
How soon should drying start?
Right away, because heat and humidity speed up mold.