Key facts: Slidell
- Slidell sits about 13 feet above sea level and roughly 3 miles north of Lake Pontchartrain, and averages about 66 inches of precipitation a year.[1]
- During Katrina, surge passed 10 feet in parts of the city, and unincorporated areas to the south and east saw 13 to 16 feet.[1]
- A tornado struck southern Slidell in April 2024, and 7 inches of snow fell in January 2025.[1]
Rebuilt next to unrebuilt
During Katrina, surge passed 10 feet in parts of the city, and unincorporated areas to the south and east saw 13 to 16 feet.[1] Elevated homes now stand beside older houses at grade. Those two neighbors can have completely different losses from the same storm.
A closer look in Slidell
A wider weather list
A tornado struck southern Slidell in April 2024, and 7 inches of snow fell in January 2025.[1] Pipes in Gulf South homes often run with little freeze protection, so an unusual freeze can do real damage.
Flood claims recorded in St. Tammany Parish
Slidell sits in St. Tammany Parish. 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 | 38,420 |
| Year with the most claims | 2005 (18,281) |
| Largest named event | Hurricane Katrina (17,945) |
| Claims outside high-risk A and V zones | 28% |
| Claims on buildings built before 1975 | 34% |
County-wide counts of insured claims only. Uninsured losses, burst pipes and appliance leaks are not in this data.
What the Slidell claim record shows
For Slidell homes, the local precedents are the events behind the most St. Tammany Parish claims: Hurricane Katrina (17,945 claims), Flooding (5,010 claims) and Hurricane Isaac (2,918 claims).
About 28% 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 Slidell home stays dry.
A newer Slidell home is not exempt: 66% of claims with a known build date involved homes built in 1975 or later.
Federal disaster history for St. Tammany Parish
FEMA lists 50 federal declarations covering St. Tammany Parish. The most common types are hurricane (29), flood (7) and coastal storm (4). The latest are Tropical Storm Arthur in 2026, Severe Winter Storm in 2021 and Hurricane Francine in 2024. If your loss falls inside an open declaration, Slidell homeowners can check DisasterAssistance.gov as well as their insurance policy.
Slidell weather and your home
Weather records for Slidell from 2015 through 2024 average 74 inches of precipitation a year, and August and June are the wettest months. The area averages 18.9 days a year with an inch or more.
Freezing nights are rare, at about 5 a year in Slidell, so the bigger concerns are storms, plumbing failures and humidity.
At 19 heavy-rain days a year, clear gutters matter in Slidell, and doors and low windows are worth watching.
When rain falls in Slidell
Seasonal averages for Slidell, 2015 through 2024. Plan roof, gutter and sump pump checks before the wettest stretch.
| Season | Average | Share of year |
|---|---|---|
| January to March | 15.7 in | 21% |
| April to June | 20.8 in | 28% |
| July to September | 23.0 in | 31% |
| October to December | 14.3 in | 19% |
Modeled from Open-Meteo historical weather data. Precipitation includes rain and melted snow.
Slidell home checklist from these records
- Don't rely on recent quiet years. Only 12% of St. Tammany Parish claims date from 2015 or later, so older floods still show what can happen.
- Test any sump pump before August, since Slidell averages 19 days a year with an inch or more.
- Keep dated photos of each room. After Hurricane Katrina, 17,945 insured St. Tammany Parish owners filed claims at about the same time.
What to tell the Slidell contractor
- Whether the home is elevated
- What the event was
- Whether power is out, for generator safety
Services Slidell callers ask about
Questions