FrostList

When to Winterize Your Boat in Brentwood, TN

ON TRACK115 days until first 28°F freezeNov 3

The first 28°F freeze near Brentwood averages November 3 (1991–2020 normals) — enough to crack an unprotected block even where owners assume they're safe — so winterize the boat by October 27. The early-odds date runs roughly 11 days ahead of the median, so build in that buffer.

OUTLOOK

Typical first first 28°F freeze near Nov 3; local deadline about Oct 27. The live 10-day outlook loads here.

Local freeze dates for Brentwood

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Oct 13Oct 26Nov 5
28°F (hard freeze)Oct 23Nov 3Nov 17
24°F (severe)Nov 1Nov 12Dec 1

NOAA station: Brentwood · 3.0 mi away · 707 ft elevation.

Numbers for Brentwood come from Brentwood, 3.0 miles away at 707 feet, where the medians fall 32°F by Oct 26, 28°F by Nov 3, 24°F by Nov 12. Year to year the 28°F date has ranged from Oct 23 to Nov 17 — about 25 days apart. Spring's last 32°F freeze clears around Apr 15. Snowfall averages 5 inches a year, first reaching an inch near January.

In Brentwood, freezing nights (32°F) typically begin around Oct 26 and the first hard freeze (28°F) follows near Nov 3. The 32°F date swings from Oct 13 at its earliest to Nov 5 at its latest, near 23 days. The last spring freeze averages Apr 15 and as late as May 4, which sets the safe window for reopening outdoor water and de-winterizing gear. At about 5 inches of snow a year, the freeze — not snow load — is the thing to plan around.

Your boat checklist

  1. Change the engine oil and filter while the motor is warm so contaminants leave with the old oil.
  2. Run the engine on antifreeze until pink fluid reaches the outlet, protecting the block and manifolds.
    Helpful gear: Marine antifreeze — Recommended pick
  3. Fog the cylinders with fogging oil as the engine runs down to coat internal parts against corrosion.
    Helpful gear: Fogging oil — Recommended pick
  4. Top off the fuel tank and add stabilizer to limit condensation and protect ethanol-blend fuel.
    Helpful gear: Marine fuel stabilizer — Recommended pick
  5. Drain the raw-water system, the livewell, and any washdown lines that can trap water.
  6. Remove the battery, charge it fully, and keep it on a maintainer over the layup.
    Helpful gear: Battery maintainer — Recommended pick
  7. Support the cover so snow and rain shed off, and leave vents so the interior can breathe.
  8. For an inboard or sterndrive, follow the manual closely — those blocks are the ones freeze claims hit hardest.

What to have on hand

Marine antifreeze
Propylene-glycol fluid rated for engine blocks and systems.
Recommended pick
Marine fuel stabilizer
Additive that protects ethanol-blend fuel over the layup.
Recommended pick
Fogging oil
Spray that coats cylinders against corrosion in storage.
Recommended pick
Battery maintainer
Keeps the cranking battery topped off on the trailer.
Recommended pick

What this means locally

Compared with nearby cities, Brentwood's first-freeze date near Nov 3 sits about a week ahead of Franklin (Nov 10) and about a week ahead of Nashville (Nov 9). Tennessee's deadlines span Oct 23 to Nov 21 statewide — one date for all of Tennessee would be off by weeks for Brentwood. Once you know Brentwood's freeze date, use it to winterize an RV and store a motorcycle too.

Other winter jobs in Brentwood

Every task below is dated to Brentwood's own freeze and snow normals.

Sprinklers → Oct 24Frozen pipes → Oct 13Ice dams → Dec 16Car battery → Nov 3Snow blower → Dec 25Sump pump → Apr 15RV → Oct 24Motorcycle → Oct 26

See the full Brentwood winter checklist, in order →

Frequently asked questions

At what temperature does a boat engine block crack?
Trapped water in an engine block or manifold can freeze and crack the casting once temperatures fall below 32°F and stay there long enough. Inboard and sterndrive blocks hold the most water and are the most vulnerable. Draining fully and adding antifreeze before the first hard freeze near Nov 3 is the protection.
Do outboards need winterizing?
Yes. An outboard should be drained so no water sits in the powerhead or lower unit, and the fuel system stabilized. Outboards self-drain better than inboards when tilted down, but fogging the cylinders and changing the gear oil are still part of a proper layup.
Fogging oil: is it necessary?
Fogging coats the cylinder walls and internal parts with a film that resists corrosion during months of storage. On engines that sit all winter it is cheap insurance against rust, especially in humid or coastal storage. Follow your engine maker's guidance on how to apply it.
How much does boat winterization cost?
A professional winterization varies with engine type and boat size, and inboards cost more than a simple outboard. Doing it yourself costs mainly antifreeze, oil, and fogging oil. Either way, the bill is far smaller than repairing a cracked block, which is the failure winterizing prevents.
Do boats in TN really need winterizing?
If temperatures reach freezing where the boat is stored, yes. Freeze claims are common in milder states precisely because owners assume they are safe and skip the step, then a rare cold snap cracks a block. Check the local freeze dates above and protect the engine before the first hard freeze.
When should I de-winterize my boat?
De-winterize in spring once the risk of a hard freeze has passed for your area. Reconnect and charge the battery, replace drain plugs, check hoses and clamps, and inspect the fuel system before the first launch. Reopening too early leaves the block exposed to a late cold snap.

Data: NOAA 1991–2020 normals via Brentwood, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.