Why Are My Car Windows Fogging up on the Outside?

Your car’s windows are fogging up on the outside because of the temperature difference between the inside of your car and the outside. As the warm air from inside your car passes through a cold window, it condenses into water droplets that form on the glass.

This is called internal condensation and occurs when there is a significant temperature difference between two objects. The best way to prevent this is to use a defroster to warm up your windows before you start driving, or use a dehumidifier in your car if it’s too humid outside.

The more moisture in the air around your vehicle, the more likely it will be for condensation to occur on both sides of the window, which means that you’ll have even more fog than usual.

What causes the windows to fog up?

The weather is too cold. The colder the temperature outside, the more moisture will be present in the air this can cause condensation on your windows when you first start driving.

If you live in an area where it’s cold all year round, you might want to try a dehumidifier in your garage before leaving for work so that there isn’t excess moisture when you get into your car.

You could also try putting up window deflectors these are thin plastic sheets that attach to your windows to keep them from fogging up during cold weather. You are running the air conditioner or heat inside your car.

When you run either of these, they remove heat from inside your car and transfer it out onto the windows, causing them to fog up as they cool down again. If possible, try turning off either system while driving so that they aren’t working against each other and making things worse.

You have been parked outside for too long without using any heating or cooling systems at all this is why leaving a wet towel on top of a bucket creates foggy condensation inside.

Why do my car windows fog up?

There are a few different reasons why your car windows might fog up, and they all have to do with either moisture or temperature. If the weather is humid, water will be in the air and you may find that when you’re driving in that weather, your windows fog up. That’s because the water in the air condenses into droplets on the inside of the windshield and causes it to mist up.

Why does the windshield fog up more than the other windows?

There are a few reasons why your windshield may fog up more than the other windows, and they’re all related to where the air is coming from. The first is that you have an air leak in your car. If you’ve ever heard a whistling noise coming from the outside of your car, or noticed water dripping down the side of it, that could be an indication of an air leak.

The water on the outside of your car could be condensation from the humidity inside cooling off and turning back into water vapor. Another reason is that you have a temperature difference between inside and out.

This can be caused by anything from strong air conditioning to hot engine coolant getting blown around by fans or vents. If this is happening, it could also cause condensation on other windows besides just your windshield.

How to prevent fogging of your car windows?

Open your windows

If you have a window that won’t open all the way, then this tip is especially helpful! Turn off your air conditioning and open the window slightly. The breeze will help clear off any fog that has formed on your windshield or side windows.

Open a window vent halfway

If you don’t want to open both front doors at once, try opening one door and leaving it slightly open while you drive. This will allow airflow into the car without letting rain get in as easily because only half the door will be open at any given time instead of both doors being wide open simultaneously like when both doors are fully opened at once (which allows more water inside).

Use a towel or newspaper

Fold up some paper towels or newspapers into small squares before putting them inside plastic bags. You can also use old cotton socks instead if these aren’t available where you live.

Cold outside weather

Cold outside weather can cause your car windows to fog up on the inside. This is because cold temperatures cause moisture to form on the inside of your window, and the warm air from inside your car condenses this moisture into water droplets. These droplets then cling to your window and cause it to fog up.

The best way to prevent this from happening is by keeping your car well-ventilated. If you have a window defroster, use it frequently (but not while driving!) to keep all of the windows clear of fog.

You can also use an air purifier in your car, which will help keep the air nice and dry by removing any excess moisture in it before it has a chance to condense on your windows.


Your car windows may be fogging up on the outside because of a variety of factors. The first thing to do is check your windshield’s defroster settings if they’re turned up too high, you can damage your window. If that doesn’t help, you may need to go for a drive in the rain or snow that will clear up any moisture that may have gotten trapped inside.

If those solutions don’t work, try a good windshield wiper fluid with anti-fog additives. If all else fails, bring it into your mechanic and see if they can find a solution.

Steven Hatman
Steven Hatman

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