FrostList

When to Winterize Your Boat in Lee's Summit, MO

ON TRACK115 days until first 28°F freezeNov 3

Plan to haul out and winterize your boat in Lee's Summit by October 27. The first 28°F freeze near Lee's Summit averages November 3 in the 1991–2020 normals, and freeze damage often surprises owners in milder states. It's a short step from frost to a hard freeze: roughly 8 days on average.

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 Lee's Summit

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Oct 11Oct 26Nov 6
28°F (hard freeze)Oct 19Nov 3Nov 17
24°F (severe)Oct 30Nov 10Nov 26

NOAA station: Lees Summit Reed Wr · 3.3 mi away · 1,000 ft elevation.

Lee's Summit draws its numbers from Lees Summit Reed Wr, 1,000 feet up and 3.3 miles away. Its median first-freeze dates are 32°F by Oct 26, 28°F by Nov 3, 24°F by Nov 10. Year to year the 28°F date has ranged from Oct 19 to Nov 17 — about 29 days apart. Spring's last 32°F freeze clears around Apr 13. Snowfall averages 17 inches a year, first reaching an inch near November.

Expect the first frost near Oct 26 in Lee's Summit and the first hard freeze by about Nov 3. Year to year, the first 32°F night has fallen anywhere from Oct 11 to Nov 6 — about 26 days apart. Spring's final freeze lands near Apr 13 and as late as Apr 28, so that is when outdoor water and stored gear can safely come back online. Snowfall averages roughly 17 inches a year — enough that a working snow blower and a clear roof edge earn their keep.

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

Lee's Summit freezes about a week ahead of Blue Springs (Nov 7) and close to Independence (Nov 5) — a reminder that even nearby towns differ by days. Statewide, Missouri prep dates run Oct 19 through Nov 8, which is why Lee's Summit gets its own number rather than a Missouri-wide average. The same freeze also decides when to winterize an RV and store a motorcycle.

Other winter jobs in Lee's Summit

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

Sprinklers → Oct 24Frozen pipes → Oct 11Ice dams → Oct 16Car battery → Nov 3Snow blower → Oct 25Sump pump → Apr 13RV → Oct 24Motorcycle → Oct 26

See the full Lee's Summit 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 MO 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 Lees Summit Reed Wr, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.