Updated at: 03-08-2022 - By: Lucas

Fogged-up car windows are a typical occurrence, especially during the winter months when humidity levels are high. Getting to the bottom of what’s causing this is critical since it could result in a harmful annoyance, such as poor visibility when driving, which increases the risk of a collision.

It’s critical to realize that automobile windows come in a variety of gradations of quality. It all depends on the make and model, but if the windows are treated with the right ingredients and have the ability to be heated electrically, you may never witness a foggy window.

If your car has an electric windscreen heater, you won’t have to turn on the heater or air conditioner to get the windows dry as quickly. When it’s cold outside, this feature will help clear the windows of ice and snow in no time.

If you’re looking to buy a new automobile, you can add this feature to your list of must-haves, but newer models already include it as standard.

What causes the car windows to fog up?

Car Windows Fogging Up Inside When Driving

When it rains, when it’s cloudy, and when there’s a lot of humidity, you’re more likely to see steam on the windows of your automobile.

Driving in foggy weather can be dangerous because visibility is usually low and all windows are likely to become foggy. In other cases, the fogged-up windows are caused by factors other than the weather.

To protect the windows from sweating, you must know what you should do in this situation. Let’s look at what’s causing this.

Colder temperatures

Condensation accumulates on the windows of a car in the winter because of the interaction between the cabin’s warm air and the cold air outside. The windows become foggy because of the buildup of this condensation.

High humidity

When it’s pouring, this is another prevalent cause. Due to an increase in cabin humidity, this occurs. Furthermore, after the heating is turned on, the driver or passenger’s wet garments and wet rugs begin to actively evaporate.

Problems with the cabin filter

Adding air from the outside can be difficult with a dirty cabin filter that hasn’t been replaced in a while.

Additionally, if the cabin filter is installed incorrectly or has flaws or model mismatches, it will result in misted windows.

Air recirculation is turned on

The ability to recirculate cabin air is currently standard equipment in the vast majority of automobiles. This choice prevents fresh air from entering the interior. This function can be handy in some instances because it keeps outside dust and scents out of the automobile.

Turning on recirculation will speed up the process of warming or cooling the inside, but it will also cause the windows to fog up. Turning off the recirculation is a straightforward solution to this problem.

Occasionally, this feature has malfunctions, such as a jammed valve that prevents the cabin from receiving fresh air from the outside. However, these instances are quite rare.

Coolant leaks

The coolant may spill into the cabin if the heater radiator or any of its branches were to burst. Oily window wetness is a result of this.

Even if the leaks are only on the passenger side, you must act promptly to identify the source in order to avoid further cooling system damage.


When someone has been drinking alcohol, their breath will produce alcohol vapors, which will cause the windows of an automobile to get foggy as a result.

How to prevent car windows from fogging up?

Car Windows Fogging Up Inside When Driving-2

Identifying and then resolving the underlying cause of fogged-up automobile windows should be your first priority. In order to avoid the repercussions, you can wipe the glass anytime it gets dirty. However, this is only a waste of time and does nothing to alleviate the problem.

You can also use the car’s air system to dry out the windows, but you’ll have to wait a long time for the motor to warm up, especially if you’re starting the vehicle from a cold starting position.

In order to get better results, you can turn on your air conditioner, but this will raise your fuel use and reduce the AC’s capacity.

The following is a list of helpful hints for keeping the windows of your car clear of condensation. However, before using them, be sure to clean the windows from the inside with a paper towel or dry cloth.

  • Lemon. Cut it in half and wipe the glass with it. Fogging will stop and you will also get a pleasant smell in the cabin;
  • Soap. It doesn’t matter what type of soar it is. Just apply it to the surfaces of the windows, then wipe the entire area with a dry cloth and then with a paper towel. Here you can also use shaving foam, it works the same way, but thanks to its semi-liquid state, the process is faster
  • Regular salt. Rub the glass surface with it, and as a preventive measure, place the salt in small bags on the center console or dashboard;
  • Alcohol solution in glycerin in a ratio of 1:20. Treat the surfaces with a clean cloth or a sprayer, then wipe the glass.

To keep the windows from fogging up, you should inspect the car’s ventilation system on a regular basis, including checking the heater and fan, as well as the cabin filter. Be sure to switch off the recirculation system as well.

Sticking a protective film on the windows can also help prevent them from fogging up. Moisture accumulation is also prevented by using this type of film.

Another option is to use an anti-fogging spray on the windows of your vehicle. After washing, drying, and degreasing the windows, the solution is applied. The approach works in the real world, although it only lasts 10 to 15 days on a single application.

You can make your own anti-fogging solution by mixing ethyl alcohol and glycerin together with a small amount of water. Glycerin has a molecular weight of 1, hence the ratio is 20.1. After that, the mixture is poured into a spray bottle for easy use.

How to properly remove moisture from the windows inside the car


As you can see, maintaining the best possible cabin ventilation is critical to preventing the interior of the vehicle from becoming fogged up as a result of inclement weather. Instead of waiting for the heater to dry off the moisture, it may be wiser to open the windows a smidge.

The correct cabin filter must be used, and it must also be replaced on schedule. Consider purchasing a more expensive carbon filter rather than an aftermarket carbon filter if you have any doubts about its quality. In addition, the filter must be placed properly.

Also, avoid leaving wet items inside the vehicle, such as shoes or jackets, because as the moisture dries, it will collect on the windows. Draining the water and wiping down the rubber matting is also a good idea. Separate drying is required for all fabric mats.

For cars that have spent long periods of time in high humidity, it is essential to thoroughly dry the interior. A warm garage or parking lot can be used to keep the windows slightly open for several days.

Driving with the side windows open if the windows begin to fog up is recommended if the heater and/or AC are unable to clear them. It’s also a good idea to leave the windows open for at least five minutes after you finish driving to let in some fresh air if it’s cold and humid outdoors.