Updated at: 24-06-2022 - By: Lucas

There are many annoying things about driving a car, such as getting stuck in traffic, people honking for no reason, drivers cutting into your lane, etc. These are things over which we don’t have much say.

But we can fix an important problem: windows that fog up in the summer, monsoon, and winter. We only think about this problem when the windows start to fog up. Then you forget what you were going to do.

I had to force myself to think about condensation and evaporation when I ran into this problem recently. Even though we came to a good conclusion, it made the fog even worse. In the end, I reached into the door pocket for the microfiber cloth and wiped away the fog.

I didn’t think this would be this hard. So, when I got home, I went online to look for the best way to stop my car windows from fogging up. I found several pieces of information that were at odds with each other, but there was one that always works for me.

To get rid of winter fog on the windshield, turn the heater all the way up, press the AC button, turn off the air recirculation switch, and crack the windows.

Why do the windows fog up?

When your car window is cold and the humidity in the air is high, fog forms (outside or inside cabin). When moist air touches cold glass, water vapour starts to form on top of it. This is called “fogging.”

Defogging in Winters

Defog Windshield-2

When it’s cold outside, the inside of the car starts to fog up. This happens because the glass in the car is cold, and when you sit in the car, moisture from the air condenses on the glass. As we breathe out water vapours, the humidity in the car is high. Let’s look at the best way to clear frosty windows in the winter:

1) Turn the heater all the way up: Fun fact: Hot air at 103° Fahrenheit/40° Celcius holds over ten times more moisture than cold air at 36° Fahrenheit/2° Celcius. So turn the heater all the way up so the air can hold more water.

Step 2) Press the AC button. When you press the AC button, the air will flow over the cool AC coils. As condensation forms on the cold AC coils, this is how the dry air will get into the cabin. Ever look under your car and see a pool of water? That is the moisture from the air conditioner’s coil.

Step 3) Turn off recirculation (get fresh air from outside): We already know that cold air holds less moisture. We want to bring this cold air in and warm it up so that it can soak up more water. So, we will stop the air from going back and forth.

Step 4: Open the windows a little bit. Cracking open the side windows lets hot air out and cold air in. This works right away to clear up fog, both in the winter and summer.

Defogging Windshield during summers

During the summer, fog forms outside the cabin. This is because the air outside is humid and the glass is cold. Let’s look at how to handle it:

1) Turn down the air conditioner’s temperature (make it hotter): You need to raise the temperature of the windshield because the cold glass is what’s making the fog. So turning down the speed and temperature of the AC fan would help.

2) Use the windshield wipers. Since the fog is building up on the outside of the windshield, it’s easy to get rid of it with the windshield wipers. When it’s foggy, the wipers might not move smoothly, so it’s a good idea to spray a little washer fluid as well.

3) Crack the windows: In this case, too, cracking the windows helps because air flow reduces the difference in temperature between the inside and outside.

Defogging in Monsoons

When it rains, the outside or the inside of the glass can fog up. Usually, the air gets more humid right after it rains. This means that the air outside has more moisture, which can cause your cold windshield to fog up on the outside.

But if it rains, the glass can get cold and fog up on the inside. If the air is humid and the glass is cold, the windows will fog up. If your clothes were wet before you got in the car, the inside will fog up more. When the water from your clothes evaporates inside the car, it adds to the amount of moisture in the cabin air.

You know how to clear the fog in either case. See the section on clearing fog in the summer and winter above.

Things you can do to help that make sense in either case: Stop recirculating the air and open the side windows a little bit.

How to prevent fogging up of car windows

It would be great if car windows never fogged up. This is possible, but the glass will need to be prepared. There are a few tricks and products you can use to keep your car’s windows from getting foggy. Let’s talk about each one:

1) Keep the glass clean. Glass that has dust and oils on it is more likely to fog up than glass that is clean. Moisture is drawn to dust particles, and when that happens, water drops form on the cold glass. It should be fine with a clean microfiber cloth and some glass cleaner. Every car detailing kit needs to have a glass cleaner.

2) Cat Litter in Socks: Cat litter can help pull moisture out of the air. Put cat litter in socks and put them near the windshield. This will help dry out the air so that the windshield doesn’t get wet.

3) Silica gel sachets: Silica balls soak up moisture from the air, just like kitty litter. Because of this, you’ll find them in shoe boxes, bags, and other clothes. Just save those silica sachets and put a couple of them near the car’s windshield.

4) Shaving Foam: This is one of the easiest ways to get the windshield ready so that it won’t fog up. Just spray some foam from the shaving can onto the windshield and spread it around. Then, wait 2 to 3 minutes and use a clean microfiber cloth to wipe it clean. This process puts a very thin layer on the surface of the glass that keeps it from getting foggy. After a few weeks, you’ll have to do this process again.

5) Shine Armor Anti Fog: This is one of the best-selling products on Amazon for preventing fog. Like the shaving foam method, this one also works. The coating, on the other hand, lasts a lot longer. The reviews from customers seem to be pretty good, so you should try it.

How to defog your windshield?

To get rid of winter fog on the windshield, turn the heater all the way up, press the AC button, turn off the air recirculation switch, and crack the windows.

How to prevent car window fogging up?

Keep the glass clean, keep a bag of kitty litter or silica gel near the windshield, clean the glass with shaving foam, and use a product designed to keep the glass from fogging up.