Williamson County, Tennessee · Franklin
Water spreading, a burst pipe, sewage, mold or smoke? Call to be connected with a restoration company that serves Franklin, Brentwood and Nolensville. Start the steps below while you wait.
Answered 24/7 by a participating local provider. We're a referral service and don't do the work ourselves. How it works
Start here
Pick the closest match. These steps limit the damage and protect your insurance claim. Skip anything that isn't safe.
Williamson County averages 12 nights a year at 20°F or colder, mostly December to February, and 4% of its homes predate 1960.
Heavy rain days of an inch or more come about 11.6 times a year here, most often in February. A sump pump that hasn't run since last season is a common weak point.
Backups often follow heavy rain, which Williamson County gets about 11.6 days a year, when storm water overloads sewer mains and pushes up through the lowest drain in the house.
Roof leaks here come from summer downpours and, with about 60 freeze-thaw days a year, from winter ice dams. Most show up as ceiling stains in the room below.
3% of occupied homes in Williamson County heat mainly with wood or propane, below the Tennessee county median of 7.8%.
About 77 nights a year here stay at 65°F or warmer, so basements and crawl spaces can grow mold even without a leak.
Local risk profile
Williamson County covers 583 square miles of central Tennessee, with about 260,351 residents and 96,921 homes. Franklin is the county seat; Brentwood, Nolensville and Fairview are the next largest communities. Much of its housing is recent, with a median build year of 2002.
31/100 Water Damage Risk Index: Moderate Williamson County ranks 86 of 95 Tennessee counties. See the statewide ranking and method.The three factors where Williamson County ranks highest compared with other Tennessee counties.
Williamson is on the colder side of Tennessee for pipes. It averaged 65 freezing nights a year over 2015–2024, 12 of them at 20°F or colder, cold enough for pipes in outside walls and crawl spaces to freeze. Among 95 Tennessee counties that's 31st.
Cold snaps are the real risk. The worst in the record lasted 7 days below freezing (ending February 2021), and the low bottomed out near -6°F on January 17, 2024.
The freeze season here runs December to February, with January the coldest. If you travel then, leave the thermostat at 55°F or above and open sink cabinets on outside walls.
On average the first fall freeze arrives around Nov 4 and the last spring freeze around Mar 30.
Williamson gets fewer downpours than most Tennessee counties, but they still fill basements. The county gets about 53.1 inches of rain and melted snow a year, with 11.6 days of an inch or more (79th of 95). Those downpours cluster in February, March and April, when sump pumps and gutters are tested hardest. The wettest day on record brought 3.81 inches on March 28, 2021. Multi-day storms matter most for basements; the wettest three days on record here totaled 5.73 inches (through March 28, 2021).
About 60 days a year swing from below freezing at night to above freezing by day. Those freeze-thaw cycles feed ice dams on roofs, open cracks in foundations and driveways, and stress pipes that are already marginal.
Housing
16% of homes in Williamson County predate 1980, below the Tennessee county median of 41.2%, which ranks 95th of Tennessee's 95 counties.
Growth since 2000 added 53% of today's homes. In houses that new, the weak points are washing machine hoses, ice maker lines, water heaters and sump pumps rather than the pipes in the walls.
30% date from 1980 to 1999, the window when polybutylene, a gray flexible plastic supply pipe, was used in some homes. It's prone to leaks at the fittings, so it's worth checking for in a house from those years.
Beyond water
About 77 nights a year in Williamson County stay at 65°F or warmer, a sign of muggy summer air (38th of 95 counties). February is the wettest month. Keep indoor humidity under 60%, as the EPA advises, and dry any leak within 24 to 48 hours; in a humid month a wet basement left alone won't dry by itself.
Mold remediation: what to expectMain heating fuel in Williamson County's occupied homes: 53% utility gas, 43% electric, 3% propane and under 1% wood. Fires here are likelier to start in the kitchen or the wiring than in the furnace. After any fire, keep the HVAC off until ducts are checked, or soot will travel through the house.
Fire and smoke cleanup: first stepsCoverage
Calls connect to restoration companies that work across Williamson County. The largest communities by population:
Population from ACS 2020-2024 5-year estimates. Townships and unincorporated areas are covered too.
Nearby
Cheatham and Dickson get more pipe-freeze nights than Williamson. Davidson County has the oldest housing nearby, with 41% of homes built before 1980.
By the numbers
| Factor | Williamson | Tennessee median | Rank |
|---|---|---|---|
| Homes built before 1960 | 4.4% | 16% | 95 of 95 |
| Homes built before 1980 | 16% | 41% | 95 of 95 |
| Homes built 2000 or later | 53% | 27% | 1 of 95 |
| Manufactured or mobile homes | 1.5% | 16% | 93 of 95 |
| Vacant homes | 4.9% | 12% | 94 of 95 |
| Wood or propane heat | 3.2% | 7.8% | 82 of 95 |
| Nights at 20°F or colder | 12/yr | 11/yr | 31 of 95 |
| Days with 1 inch+ of rain | 12/yr | 14/yr | 79 of 95 |
| Freeze-thaw days | 60/yr | 60/yr | 48 of 95 |
| Muggy nights (65°F+) | 77/yr | 74/yr | 38 of 95 |
Rank 1 is the highest value. Bars run from the lowest to the highest Tennessee county; the tick marks the median; orange means higher water damage risk than the median, green means lower.
Questions
Peak risk months in Williamson County: freezing from December to February, heavy rain in February, March and April.
Sources: U.S. Census Bureau, ACS 2024 5-year estimates (2020-2024); weather from NOAA nClimGrid-Daily county averages (EpiNOAA), 2015–2024, averaged across the county; county boundaries from Census TIGER. Reviewed 2026-10-21. Methodology