FrostList

When to Winterize Your Boat in Terre Haute, IN

ON TRACK111 days until first 28°F freezeOct 30

Plan to haul out and winterize your boat in Terre Haute by October 23. The first 28°F freeze near Terre Haute averages October 30 in the 1991–2020 normals, and freeze damage often surprises owners in milder states. Plan for the early end: the one-in-ten date lands about 16 days before the median.

OUTLOOK

Typical first first 28°F freeze near Oct 30; local deadline about Oct 23. The live 10-day outlook loads here.

Local freeze dates for Terre Haute

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Oct 4Oct 19Nov 2
28°F (hard freeze)Oct 14Oct 30Nov 14
24°F (severe)Oct 25Nov 10Nov 30

NOAA station: Terre Haute Indiana State · 0.4 mi away · 507 ft elevation.

The reference station for Terre Haute is Terre Haute Indiana State (0.4 mi, 507 ft). First freeze there: 32°F by Oct 19, 28°F by Oct 30, 24°F by Nov 10. The 28°F freeze has come as early as Oct 14 and as late as Nov 14, a 31-day spread. Spring's last 32°F freeze clears around Apr 15. Snowfall averages 15 inches a year, first reaching an inch near December.

Expect the first frost near Oct 19 in Terre Haute and the first hard freeze by about Oct 30. That first freezing night has ranged from Oct 4 to Nov 2, roughly a 29-day spread. On the spring side, the last 32°F freeze clears around Apr 15 and as late as May 3 — the green light for reopening water and de-winterizing. With around 15 inches of snow annually, plan for a handful of plowable storms each winter.

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

Terre Haute freezes about a week ahead of Bloomington (Nov 4) and close to Urbana (Nov 2) — a reminder that even nearby towns differ by days. Statewide, Indiana prep dates run Oct 21 through Nov 13, which is why Terre Haute gets its own number rather than a Indiana-wide average. The same freeze also decides when to winterize an RV and store a motorcycle.

Other winter jobs in Terre Haute

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

Sprinklers → Oct 20Frozen pipes → Oct 4Ice dams → Nov 15Car battery → Oct 30Snow blower → Nov 24Sump pump → Apr 15RV → Oct 20Motorcycle → Oct 19

See the full Terre Haute 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 Oct 30 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 IN 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 Terre Haute Indiana State, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.