FrostList

When to Winterize Your Boat in Monroe, LA

ON TRACK141 days until first 28°F freezeNov 29

Freeze protection for a Monroe boat keys off the first 28°F freeze, which averages November 29, so haul out and winterize by November 22 to beat it. Year to year the date swings about 46 days, which is why the live outlook beats the calendar.

OUTLOOK

Typical first first 28°F freeze near Nov 29; local deadline about Nov 22. The live 10-day outlook loads here.

Local freeze dates for Monroe

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Nov 1Nov 15Dec 3
28°F (hard freeze)Nov 9Nov 29Dec 25
24°F (severe)Nov 21Dec 18Jan 18

NOAA station: Monroe Rgnl AP · 4.6 mi away · 79 ft elevation.

The reference station for Monroe is Monroe Rgnl AP (4.6 mi, 79 ft). First freeze there: 32°F by Nov 15, 28°F by Nov 29, 24°F by Dec 18. That hard freeze has landed anywhere from Nov 9 to Dec 25, a swing of roughly 46 days. Spring's last 32°F freeze clears around Mar 8. Snowfall averages 1 inches a year.

In Monroe, freezing nights (32°F) typically begin around Nov 15 and the first hard freeze (28°F) follows near Nov 29. Year to year, the first 32°F night has fallen anywhere from Nov 1 to Dec 3 — about 32 days apart. Spring's final freeze lands near Mar 8 and as late as Mar 25, so that is when outdoor water and stored gear can safely come back online. Measurable snow is rare, so the freeze near Mar 8 — not snow load — drives the local prep list.

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

Against its neighbors, Monroe (first freeze Nov 29) runs about a week ahead of Alexandria (Dec 13) and about a week ahead of Bossier City (Dec 10). Across Louisiana, local prep deadlines in our data range from Jan 1 to Dec 31, so a statewide rule of thumb would miss Monroe by weeks. In Monroe, that same cold is your cue to winterize an RV and store a motorcycle.

Other winter jobs in Monroe

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

Sprinklers → Nov 19Frozen pipes → Nov 1Car battery → Nov 29Sump pump → Mar 8RV → Nov 19Motorcycle → Nov 15

See the full Monroe 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 29 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 LA 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 Monroe Rgnl AP, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.