FrostList

When to Winterize Your Boat in Lodi, CA

ON TRACK162 days until first 28°F freezeDec 20

Freeze protection for a Lodi boat keys off the first 28°F freeze, which averages December 20, so haul out and winterize by December 13 to beat it. The early-to-late range spans roughly 55 days, so treat the median as a midpoint, not a promise.

OUTLOOK

Typical first first 28°F freeze near Dec 20; local deadline about Dec 13. The live 10-day outlook loads here.

Local freeze dates for Lodi

ThresholdEarly (1-in-10)MedianLate (9-in-10)
32°F (light freeze)Nov 17Dec 5Jan 3
28°F (hard freeze)Nov 30Dec 20Jan 24
24°F (severe)Dec 9Jan 1Jan 31

NOAA station: Lodi · 2.1 mi away · 40 ft elevation.

The reference station for Lodi is Lodi (2.1 mi, 40 ft). First freeze there: 32°F by Dec 5, 28°F by Dec 20, 24°F by Jan 1. That hard freeze has landed anywhere from Nov 30 to Jan 24, a swing of roughly 55 days. Spring's last 32°F freeze clears around Feb 9.

Lodi usually sees its first 32°F night about Dec 5, with the first 28°F hard freeze close behind near Dec 20. The 32°F date swings from Nov 17 at its earliest to Jan 3 at its latest, near 47 days. The last spring freeze averages Feb 9 and as late as Mar 7, which sets the safe window for reopening outdoor water and de-winterizing gear. Snow barely registers here; the freeze date, around Feb 9, is the one that matters.

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

Lodi freezes close to Stockton (Dec 23) and later than Elk Grove (Dec 16) — a reminder that even nearby towns differ by days. Statewide, California prep dates run Jan 9 through Dec 30, which is why Lodi gets its own number rather than a California-wide average. The same freeze also decides when to winterize an RV and store a motorcycle.

Other winter jobs in Lodi

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

Sprinklers → Dec 10Frozen pipes → Nov 17Car battery → Dec 20Sump pump → Feb 9RV → Dec 10Motorcycle → Dec 5

See the full Lodi 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 Dec 20 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 CA 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 Lodi, live outlook by Open-Meteo. Sources · Methodology. Last updated: July 11, 2026.