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When to Winterize Your Boat? – Winterization Checklist

Written by J. Harvey / Fact checked by S. Numbers

when to winterize your boat

As a newbie boat owner, knowing when to winterize your boat can be confusing since there’s no specific date or month recommended.

In some ways, it’s dictated by a combination of variables for which you must be ready to adjust. The main factors to look at are your local climate and temperature fluctuations.

Generally, if temperatures fall below freezing levels (-3°C), it’s time to consider winterizing your boat. If you live somewhere where the winters can be brutal, make it a habit to do it once the boating season concludes. In addition, storing the boat for more than a month also requires winterization.

The Best Time to Winterize Your Boat


To most boaters, the best time to winterize your boat is a month or a few weeks before the temperatures decrease to the point that it puts you at risk of a boat freeze in one night. Look up the weather forecast in your region to expect when the first frost will hit.

Also, there’s no harm in winterizing your boat once you decide to store it for more than 30 days up to a year. It’s a preventative strategy that puts it a step ahead of corrosion and other damage risks. Wouldn’t you settle for anything less in protecting your prized investment?

I mean, how long does it take to winterize a boat? It’s not like it would eat up an entire week. Most experienced boat owners can finish it in an hour up to a full day; it’s especially the former case if the aim is to just winterize a ski boat or a smaller vessel.

If you really want a timeframe, then refer to the table I’ve prepared below. I suggest you just regard the month range as your upper limit, as well as the best times to consider packing your season’s bags and preparing for the colder months.

US Region Typical Timeframe to Winterize
Northeast September – November
Northwest November – December
Midwest Late October – November
Southeast November – December
Southwest December – January
West October – November

Bear in mind that in Florida, California, Hawaii, and New Mexico, it’s usually not necessary to winterize boats. Most experts advocate winterizing only if there’s a chance of freezing, and based on historical temperatures in those states, those instances are rare at most.

Moreover, just because two states are adjacent to each other doesn’t mean that they have the same winterizing schedules and recommendations.

  • For example, in North Carolina, boaters are expected to have their vessels all covered up and ready by November at most. But folks just below it trawling in South Carolina or, to be exact, further down south in Hilton Head actually don’t need to winterize their watercraft.

And, thus we come to two important tips:

  • Always be ready to make adjustments based on the immediate climate and temperatures in your area at present.
  • Familiarize yourself with the specific conditions in your area come wintertime.

The Importance of Winterizing Your Boat


Why do you winterize a boat in the first place? The benefits compound, to put it mildly. Here’s why you can’t convince me otherwise that it’s not important to winterize your boat.

  • It protects your boat from damage that will inevitably reduce its lifespan. Once the water freezes, it can result in cracking in boat components that hold liquid (including precious parts like the boat’s engine).

What’s more, once the water melts come springtime, rust and mold onset can start. Every time you winterize too late, this damage will add up.

  • You’ll not only be able to save money on repairs but retain your boat’s value, too.
  • Winterizing almost always includes a full checkup of your boat. I’ve lost count of the number of times I discovered an issue or two when I performed winterizing.
  • With consistent maintenance, you’ll be able to guarantee your and your passenger’s safety every time you take it out at the start of the season.

How to Know When You Need to Winterize Your Boat

Is temperature the sole gauge for when you should start winterizing? Not really. Most of the time, you just need to exercise common sense.

For one, once you notice that the nights are getting colder and there are undeniable traces of frost on the ground, it’s time to start preparing. Just make a couple of adjustments based on how you’re using your boat at present and what the manufacturer recommends.

Boat Winterization Checklist


What do you do once it’s time to winterize your boat? Here’s my own checklist, which I’ve modified over time, based on my experience and what I’ve learned from other experienced boaters:

  • Do a thorough inspection of your boat. If there are problems, major or otherwise, be sure to address them before proceeding with the winterization process
  • Fill the fuel tank up to 90% capacity to anticipate expansion
  • Use a fuel stabilizer, then seal the valves. You should also run the boat for 10–15 minutes, so the stabilizer is evenly distributed.
  • Do an oil change and replace the filters
  • Fog and flush the engine with soapy water, rinse, then let it drain completely
  • Remove water from water separators, remove all engine drain plugs, live wells, the bilge pump, and other systems and components with any remaining moisture.

Note: Feel free to use an air compressor after replacing the water with antifreeze on the said systems. Be sure to start and idle the engine until the antifreeze escapes from the exhaust.

  • For inboard boats, use antifreeze on the tanks, blocks, and manifolds.
  • Remove the battery as well as any trace of items that aren’t essentially part of the boat, like food, drinks, clothing, valuables, and especially anything that might expire.
  • Perform general cleaning on the boat
  • Cover up the boat properly for storage

Other Tips to Remember When Winterizing Your Boat


  • To make sure that you’ll still be able to take care of any moisture you didn’t drain, store the boat with its stern pointing down to ensure rain and melted snow don’t build up on deck. This works especially well for outboards, which tend to be less of a hassle to winterize compared to inboards.
  • While some people like to winterize a boat in the water, I usually don’t do it because it immediately crosses out any opportunity for me to readily inspect or maintain it, more so the latter.
  • I’d still winterize my boat if I keep it in the garage. The heat these structures provide can only help so much, all the more so if you live in hard freeze climates.
  • Keep in mind that the boat winterization cost can be as high as $500 if you let a professional do it for you. Should you do the job yourself, you might only have to spend around $150.
  • You should be just as meticulous when checking the place you’ll be storing your boat in. I mean, what if rats have moved in there?
  • Don’t skip covering your boat with a tight-fitting tarp because even if pests have made their way into your garage, your baby will still be sufficiently protected.

For more fascinating tips, hear them first-hand from a bonafide old salt:

Frequently Asked Question

At what temperature should a boat be winterized?

The general recommendation is your boat should be winterized before temperatures fall below -3°C. It would still depend a lot on your location, though. For example, in Arizona, boaters are advised to winterize before temperatures reach -1.1°C.

How often should you winterize your boat?

Do it yearly, as part of the boat’s general maintenance. Not only does this safeguard your boat, but it helps you stay on top of problems, too.

What happens if you don’t winterize a boat?

Any remaining oil and water will freeze over and start to damage vital components, not least of which are the motor, water systems, and lines. As a consequence, you’ll likely need to have them repaired or, worse, replaced.


At the end of the day, knowing when to winterize your boat becomes an instinctual habit. If the forecasts are saying you’re in for a hard freeze or deem the season over, don’t dilly-dally or bother second-guessing yourself. What’s the harm in winterizing a little early if it’s only good for you and your boat?

Ultimately, I just regard it as my yearly maintenance work. And, based on how long my vessels have stayed in commission, it’s safe to say that my efforts have directly contributed to that.

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