How to Prevent Car Windows from Fogging Up

how you can keep your car windows from fogging up
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Have you ever been driving when all of a sudden it’s become incredibly hard to see because your car windows look like your bathroom mirror after a hot shower? That’s window fog, and it’s incredibly annoying. Worst of all, it can be extremely dangerous. 

When a car’s windows fog up, the driver loses vision of the road and the car’s surroundings which can be detrimental to the safety of the car’s driver and passengers as well as surrounding cars and pedestrians. It’s important to know how to get rid of it, and especially how to prevent it in the first place to ensure the safety of everyone. 

Here are a few tips on how to prevent car windows from fogging up:

What Causes Window Fog?

Window fog is the condensation of water on car windows due to the windows reaching the dew point. The dew point is the temperature where moisture in the air condensates and turns into water, which is why when it is cold out, you can’t see out of your windows. 

Believe it or not, there’s a lot of factors that increase the moisture of your car, and leads to fog forming on your windows.

Breathing is the most common. When you and your passengers breathe, you are breathing out small particles of water that slowly increases the moisture in the car. 

Open beverages, especially hot beverages, will evaporate causing the air in the car to become moister. Even small things like wet car seats and floors caused by rain or snow will increase the car’s moisture levels over time. With all of these in play, your windows will fog up incredibly fast once they reach the dew point.

here's how to prevent car windows from fogging up

How to Get Rid of Window Fog

It can be very scary if you’re driving and all of a sudden you can no longer see the road because the windows in the car fogged up. Many people’s first reaction is to wipe the car windows with their hands or sleeves, but that isn’t going to fix the problem. It’s only a temporary fix to your vision.

  • The most straightforward method would be to turn on your heater in the car. The heater will increase the cabin’s internal temperature and bring the windows above the dew point so the fog will go away.
  • Another method is to use your air conditioner. As long as you turn off the recirculating air setting on your car, the cold air from the air conditioner will remove the moisture out of the air. This results in the same outcome as turning on the heater, it’s merely two different ways to get there.
  • A button some may not know about is the defrost button. Cars have it near your temperature controls. It will either look like the shape of your windshield or a rectangle depending on if its for the front or rear windshield, with three squiggly arrows pointing up. That is called a defrost which when turned on will remove the fog from your windows. The defrost typically uses the air from the heater to directly blow on the glass and heat up the windows so the fog goes away.
  • You can also simply open your windows if it is a nice day out. It will circulate the air, causing the moisture to go out the window but usually, if your car’s windows are fogging up, its because the temperature outside is very cold. This may not be the most viable solution, however, it will work if you want to ride around with the windows down.

Next time your car’s windows fog up, use one of these methods. You need to increase the temperature of the windows or remove moisture from the air. Trying to only wipe away the condensation from the glass is only going to solve it for a few moments before fogging up again.

How to Prevent Window Fog

The best solution is always to prevent it from happening in the first place. This ensures you don’t need to pull over or have to fumble with your temperature controls while driving with fog on your windshield.

Ensure you and anything else you are bringing into the car is dry. If you have an umbrella, shake it off before putting it inside the car, or kick the snow off of your boots before getting in. 

The less moisture you bring in, the better.

Don’t leave open beverages in the car. You can have closed bottles, as they don’t add to the moisture in the car, but open cans or cups will cause the air to gain moisture and possibly condensate on your windshield.

You can get car silica or even fill socks with kitty litter and place it inside of your car. Either will slowly absorb all of the moisture in your car making the air far drier and in turn, reducing the risk of fog forming on the windows.

Also, make sure your windows are clean. Dirt and dust attract moisture which only makes it more likely for your windshield to fog up. You can use a windshield cleaner and lint-free cloth to wipe down the glass and then put a coat of anti-fog spray on the windows.

Taking these precautions should help you avoid window fog while you’re driving around on cold days.

a clean window is a must


Window fog isn’t fun, nor is it safe. Remember to keep the inside of your car dry and remove open beverages from the cabin. Put silica, kitty litter, or any other absorbent in your car to prevent excess moisture. Especially don’t forget to keep your windows clean and when you’re done, put a protective coat of anti-fog spray on the glass.

If you still get window fog, you know now you can use the heater, air conditioner, or defroster to remove the fog. Just make sure to turn off the recirculation setting so the moisture isn’t being reintroduced into the inside of your car.

The key is to keep moisture levels low, and the temperature above the dew point. As long as you manage that, window fog won’t be an issue for you ever again.

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