This post may include affiliate links. If you make a purchase through these links, we'll receive a commission at no extra cost to you. This support helps us maintain and grow our site. Thank you for your support!

It can be very frustrating when your car window keeps fogging up. But to prevent it you need to understand why car windows fog up in the first place.

Although car fog can seem pretty harmless, it can cause low visibility which can result in dangerous accidents. That is why you should learn how to prevent your car windows from fogging.

The main culprit of car window fog is condensation. This happens when the temperature of the inside of the car is very different from the temperature outside the car. Therefore, car window fog can occur in both the winter and summer seasons.

Fortunately, there are several easy ways to get rid of car window condensation including turning on the AC, turning on the demister or the defrost vents, opening the windows, parking the car in a garage, recirculating the air, and more.

As a person who has lost patience with the fog in his car windows, I can inform you about several tried and tested methods of preventing condensation on car windows.

Table of Contents

Why Do Car Windows Experience Fog?

Car windows experience fog due to condensation. This phenomenon occurs when the moisture in the warm air comes in contact with cold surfaces. Therefore, when the warm air inside the car meets the cold glass of the windows, water will gather on the glass making it blurry.

Car Fogging is Due to the Weather

When it is cold outside, you will notice that your car windows will instantly start to fog as soon as you get into the car (if they aren’t already fogged up).

In the summer seasons, you might experience condensation also. However, this will be to a lesser degree than what you face in winter because the cooler air inside your car does not have as much moisture as warm air outside your car. However, the most annoying thing about car window condensation in the summers is that the fog is on the outside of the window. This means you have to clean the window from the outside and if your window starts fogging up when you are driving, it will necessitate a stop.

Car Fogging Can Occur Due to Increased Moisture Content in the Car

Apart from the water, car fogging can also occur if you increase the moisture content in your car. This entails bringing in wet clothes, snowy boots, hot food, or using damp car flooring.

Solutions for Preventing Car Windows From Fogging Up

Car window fogging is inevitable, but there are several measures you can take to prevent it from happening. Let’s take a look at some of them:

Turn on the Heater

In the winter season, crank up the heater so that the fog subsides. Face the vents to the side window glass so that the heat prevents them from fogging up. This is one of the easiest methods to get rid of the fog inside the vehicle.

Keep in mind though that if the temperature inside the car rises too much, it can create fog on the outside of your window. So you need to find a proper balance in temperature to keep the fog at bay.

Use the AC

In the summer seasons, turning on the air conditioning in your car can lead to window fogging. If you want to reduce the amount of fog on the windshield and side windows, you should reduce the power of your AC. When the temperature inside the car is raised to match the outside of the car, your windows will stop fogging up quickly.

Roll Down the Windows

For all those people who are used to the summer heat, the fastest solution to defogging your windows is to roll down the windows. This will allow the outside air to flood into your car. At the same time, the temperature inside your car will match the outside temperature. You will be surprised to see that all the fog on your windows disappear within seconds with this neat trick.

Recirculate the Air

Your car has a “Fresh Air Mode” button located on the dashboard which is one of the easiest ways to defog your windows and windshield in the winter seasons. The button features an arrow pointing into the car. When you turn it on, it will bring in fresh air from the outside without lowering the temperature of your car. In fact, the temperature of your car will be quite balanced, allowing the fogs on the glass to subside.

Before doing this, make sure the “Recirculation Mode” is turned off. This option closes the air ducts in the car and circulates the air inside.

Turn on the Windshield Wipers

Since condensation in hot weather occurs on the exterior surfaces of the glass, it is easy to remove it by turning on the windshield wipers. Your wipers are designed to get rid of excess moisture and condensation is just that. With just a few swipes of the wipers, your windshield will be clean.

If you think the wipers are just spreading the water around your windshield, spray a few squirts of cleaner on the windshield and turn on the wipers on a low setting to clean the glass well.

Use the Demister

A lot of people forget to use the demister function to clear their windshields. In most modern cars, this feature will direct the warmed air from the air conditioner to the windscreen. The car’s climate control system will also open the vents in your car to draw in the fresh air and to engage the heater for a short time to warm the glass.

Windows that are warm and dry will prevent fog from forming for longer than glass that is cold to the touch.

Press Defrost

Your car also comes with a defrost option. To ensure that your rear window is free of condensation and offers increased visibility, the defroster uses an electric element to warm the glass so that the condensation evaporates from it. This system works as efficiently as the windshield demister by eliminating the causes of window misting.

There are some cars that also use invisible elements in the windshield to get the same effect. In other cars, defrosters can also clear up the side view mirrors of your car as well.

Keep your Car Windows Clean

Road debris, oil, and contaminants like volatile compounds from the dashboard vinyl can accumulate on your window and allow vapors to form on the glass. If your glass is squeaky clean, it will reduce the surface area for moisture to hold on to. This means your glass will take longer to fog up and will quickly become clear with any fig-reducing methods.

Apply Anti-Fog Sprays

Anti-fog sprays are designed to control the humidity and the moisture inside your car. All you need to do is to spray the formula onto the exterior and interior surface of your car window. This will dry out persistent fog in an instant.

These sprays are quite cheap and can improve visibility in all kinds of weather and enhance your safety when driving.

Use Silica Balls

Silica balls are a cheap and effective way to reduce the moisture content inside your car. Since they keep food, medicine, and other products fresh and dry, they work the same way in cars. You can make a dehumidifier by placing some silica balls in a sock or tights and placing it in your car.

This will absorb the excess moisture in the car. When the sock gets wet, you can replace it.

Shaving Foam

Shaving foam is a surprising way to prevent your car from fogging. Take a fistful of shaving foam and slather it across the glass of your car with the help of a clean cloth. Allow the foam to rest on the windshield for about two minutes before you use a clean cloth to wipe it off.

The shaving foam will form an invisible protective layer on top of the windshield and will prevent the moisture from collecting on the glass, improving your visibility.

Don’t Bring in Wet Items

Not many people are aware of it but bringing wet or damp items into the car will make your windows fog up frequently. When you carry a wet umbrella, snowy boots, or damp clothes in your car, you are more likely to experience foggy windows than when your car’s interior is warm and dry.

This is a common occurrence in places where rainfall and snowfall occurs regularly. So if you have wet items with you, it is a good idea to place them in a plastic bag and store them in the car trunk so that the moisture inside of the passenger cabin does increase and lead to window fogging.

Park your Car in the Garage

To prevent your car from being fogged up in the morning, it is a good idea to park it inside a garage where there is much less moisture than the outside. In addition, if you keep your car parked outside in the open air throughout the night, after some time the moisture will seep inside your car and make your interior moist and humid.

If you do not have a garage to park your car in, try to park it in a shaded or enclosed area that does not allow much moisture circulation. This will also prevent your window from getting fogged.

Why Do Car Windows Fog Up? (List & Solutions)

About The Author

Charles Redding

Charles Redding

I've spent many years selling cars, working with auto detailers, mechanics, dealership service teams, quoting and researching car insurance, modding my own cars, and much more.

Read More About Charles Redding