If you live in very cold countries, you know frozen washer fluid in winter isn’t far-fetched. All you have to do is leave your car out in the open for long enough with the wrong washer fluid in the tank, and it will be frozen solid.
When you pull back or push away on the wiper stalk to get that glorious spritz of water, you will hear the pump whir and the wipers swish, but you’ll get no washer fluid.
While this might mean your tank is empty, it could also mean all your washer fluid is in a solid state, and the pump can’t move it.
What is the Wiper Fluid Freezing Point?
Wiper fluid freezing points vary depending on what you put in your washer fluid tank. Since people use different fluid compositions ranging from pure water to home concoctions and commercial products, it is hard to state the exact values.
Here is a look at possible washer fluids and their freezing points in degrees Fahrenheit.
| Name | Estimated Freezing Point | Get it |
| Plain Pure Water | 32°F | From your tap |
| Bug Wash | 32°F | Amazon |
| Qwix Mix Washer Fluid Concentrate | Up to -25°F with methanol additive purchased separately | Amazon |
| Peak PWN0H3 | -20°F | Amazon |
Why is My Windshield Washer Fluid Freezing?
Scientifically, your washer fluid is freezing because temperatures dip below its freezing point. This could be because:
- You are using the wrong washer fluid for prevailing temperatures
- You park your car out in the open
- You are experiencing more severe winters than you expected
Swapping your regular bug wash or freshwater with an antifreeze washer fluid rated for the temperatures you expect your winter hit is the best way out. Alternatively, you can follow these tips to keep your washer bottle contents from solidifying.
How to Keep Washer Fluid from Solidifying
Here are some more detailed and actionable steps you can use to stop your washer fluid from solidifying
Use the Correct Freeze Point Washer Fluid
When winter rolls in, the first thing to do is to replace your summer bug wash or pure water with an antifreeze wind washing fluid.
Go for a product whose freeze point is way lower than the lowest temperatures you expect on the coldest nights of winter.
Buy Commercial Antifreeze
You can opt for ready-to-use washer fluid concentrates or diluted solutions with antifreeze in place.
Alternatively, you can buy antifreeze additives made for your washer fluid or engine coolant. Most antifreeze is made of ethylene glycol. Most antifreeze solutions are designed to work as engine coolant and might not be the perfect washer fluid additive.
What Can You Put in Windshield Wiper Fluid to Keep it From Freezing?
Adding alcohol is a simple way to give any washer fluid you already have better freeze resistance. Methanol is the most commonly used alcohol for this purpose. Some people opt for ethanol as it is less toxic and easier to come by.
The amount of alcohol you add to your existing washer fluid determines how low a temperature it can survive without turning solid.
ProTip: Only add alcohol to washer fluids that already use alcohol as an antifreeze additive, or the manufacturer recommends using it. Avoid using it in products that don’t mention it as it could lead to unexpected results.
Here is a quick look at how methanol changes the freezing points of the Qwix Mix washer fluid concentrate that we recommended earlier on:
Note that the calculation is based on 1/4 oz of the concentrate making a gallon of washer fluid when diluted.
| Ounces of Methanol | Ounces of Water | Freeze Protection |
| 0 | 128 | 32°F |
| 9 | 119 | 20°F |
| 16 | 112 | 10°F |
| 25 | 103 | 0°F |
| 33 | 95 | -10°F |
| 44 | 84 | -20°F |
| 48 | 77 | -25°F |
Park Your Car in a Garage
Since very low temperatures also affect other fluids in your vehicle, parking your vehicle in a protected garage is a great idea to avoid trouble when you try to get it going.
Parking in a garage during winter is always a great idea. It protects your vehicle from being snowed in or getting splashed with salt when the de-icing truck drives by.
The simple protection from an insulated or uninsulated garage will improve the lowest temperatures your vehicle experiences, making it harder for the antifreeze in your washer fluid and engine cooling system to solidify.
It will also ensure your engine starts smoother since it will have the right viscosity of engine oil and flowing fuel for a quick start when you turn the key or hit the start button.
Heating the garage isn’t really necessary unless you live in the very cold north, where temperatures can easily dip below 50. Nonetheless, a heated garage will be a plus but not a substitute for getting the correct freeze-resistant washer fluid.
Use Engine Block Heaters
If you can’t park in a garage or live in very cold places, you could consider installing an engine block heater.
Engine block heaters are common with diesel engines frequenting freezing temperatures. They keep the motor oil from getting too thick and can also protect other fluids in the engine, including washer fluid.
They are a great solution when parking overnight in a very cold place or when leaving your vehicle parked for a while in severe winter.
Get a Windshield Washer Fluid Heater
A more specific alternative to an engine block heater is getting windshield washer heaters. Some vehicles come stock with a heater that lets you use warmed washer fluid to get ice or snow off your windshield.
This is an active way to ensure your washer fluid stays liquid. However, most heaters will only run with the engine running – unless you get one that plugs to an external power supply.
ProTip: If you live where your washer fluid keeps freezing even when using the correct freeze-resistant concoction, an engine block heater will also be a wise decision since chances are your engine is also suffering from very low temperatures.
Homemade Windshield Washer Fluid that Doesn’t Freeze
If you have no access to commercial freeze-resistant wiper fluid or can’t be bothered to purchase any, here are some alternatives and a favorite recipe you can use to whip up your freeze-resistant washer fluid.
Vinegar Windshield Washer Fluid
Vinegar, distilled or fresh water, is a great alternative to chemical-based washer fluids. Vinegar is a well-known cleaner that’s readily available in many homes.
Apart from making your water more efficient at washing the windshield, it will also lower the water’s freezing point.
- Get 3/4 gallons of soft or distilled water and pour it into a 2-gallon container
- Add four cups of white vinegar ad shake to mix thoroughly
You can test your solution by leaving it out at night in a windy place to see if it will withstand the temperature. If it freezes, consider adding some vinegar or using another anti-freeze additive.
Using Rubbing Alcohol as an Additive
We recommended using ethanol or methanol to lower the freezing point of your washer fluid. While these are the most popular alcohols for the job, you can still use alternative alcohols like rubbing alcohol.
You will have to experiment to find out how much rubbing alcohol you need to survive the lowest temperatures.
ProTip: The rubbing alcohol concentration matters. You will need less 90% rubbing alcohol to attain the same freeze resistance as you would with a given volume of 70% rubbing alcohol.
- Prepare your homemade cleaner of choice. Be it vinegar and water or window cleaner and water
- Add a cup of rubbing alcohol to a gallon of your windshield cleaner and shake thoroughly
- Take a sample in a small closed container to test how low of a temperature it can survive
- You can do the test by putting it in a freezer set to the lowest target temperature or leave it outside in winter to see if it remains liquid
ProTip: Some vehicles with automated washer fluid level readers won’t detect anything if you use a clear liquid. Adding a bit of blue food color to give your homebrew a faint blue tint will make the sensors pick up fluid levels
Who Needs Freeze-Proof Windshield Washer Fluid
Anyone living in places where temperatures dip below 32 degrees Fahrenheit needs freeze-proof washer fluid. This is the average freezing point for water where most washer fluid and bug wash products start to freeze.
How Do I Unfreeze My Windshield Washer Fluid?
Washer fluid will unfreeze as soon as ambient temperatures warm up above the freezing point. Even if you are using bug wash, chances are it will melt once the temperatures start nearing 35 degrees.
You can either achieve this by:
- Moving your car to a heated garage
- Waiting for temperatures to pick up
- Start driving and refrain from using the washer for a while. The engine’s heat should help defrost the washer fluid.
Bottom Line
Using the correct washer fluid and parking your vehicle in a protected garage during winter should protect you from the inconvenience of frozen windshield washer fluid.
Also, ensure that you changed your oil to the correct winter grade. Sluggish or solidified oil at very low temperatures is more problematic than frozen washer fluid.