How to stop car windows from fogging up

8 minute read Published on May 20, 2024 by BrokerLink Communications

Happy woman drawing a heart on a foggy car window during a rainy day.

One of the most frustrating things to deal with as a driver is your windshield fogging up. Not only can a cloudy windshield lead to distracted driving as you attempt to clear the fog, but it can also impact your field of vision. To learn more about how you can keep your car windows clear of fog, keep reading.

What causes foggy car windows

In order to keep your windows from fogging up and improve your night vision while driving, you must understand what causes your windows to fog up in the first place.

Foggy windows most commonly occur in the winter when the weather is cold, which is why a key part of getting your car winter-ready and winter car maintenance is to know what to do if your windows fog up.

When temperatures are cold outside, any moisture that is brought into the car will turn to condensation. This is due to the fact that there is a big difference between the air temperature inside your car and the air temperature outside your car. As the warm, moist air inside your car, produced by both body heat and your car’s heating system, comes into contact with the warm windows, condensation will form. In turn, this makes your windows appear foggy, reducing visibility.

Although cars in Canadian winters most commonly deal with the issue of foggy windows, it’s still possible to experience them in the summer. For example, in the summer, when temperatures are hot outside, and you get in your car and turn the air conditioning on, condensation may form on the windows due to the difference between the cool temperature inside your car and the hot and humid weather outside of it.

How to clear fogged-up windows in the moment

If you’re driving and fogged-up windows start to appear, then you need to act fast. Although defensive driving habits like keeping your distance between cars can help you avoid a collision by giving you time to react to various situations, including fogged windows, you also don’t want to be driving with fogged-up windows for too long.

First, as soon as you notice that the windows are starting to fog up, remain calm. Many drivers frantically react to the situation, which can be as dangerous as impaired driving or driving at night. So, instead, try to relax as you think through what to do next.

If you’re driving during the winter, such as driving on an icy road, then the last thing you probably want to do is turn on your car’s air conditioner (AC). That said, if you’re dealing with foggy windows, turning on the AC is a move that you should consider, as the air conditioner is probably the fastest way of de-fogging windows quickly. Why is an air conditioner so effective? AC systems remove moisture from the air, which can eliminate fog in minutes or less. So turn on the air conditioner in your car until the fog is gone, and then you can turn it off and let your car return to a warm temperature.

Another option if you need to get rid of fog fast is to turn on the heater in your car. Believe it or not, the heater can be used to get rid of fog because it increases the temperature of the window. However, to effectively use this method, it’s recommended that you turn on the demister setting so that the warm air from your car’s heating system is blowing directly onto the windshield. Please note that when using the heating or air conditioning method, do not use your car’s recirculation setting, as this will keep the moist air trapped inside your car.

A third quick and easy way to get rid of fog is to roll down your car windows. Fresh air can get rid of excess moisture quickly. However, this may not be an option at certain times of year or in certain weather conditions, such as rain.

One last short-term solution is to wipe down the windows with a cloth or sponge. However, this is only a temporary fix. As the driver continues breathing and using the car’s heating or air conditioner, the condensation will likely return and keep fogging up the windows. That said, carrying a cloth with you can be an easy remedy that takes you time to develop a longer-term solution.

How to prevent foggy car windows in the future

If you want to learn how to avoid foggy car windows in the first place, which can help you avoid a collision and having to file a car insurance claim, keep reading:

Heat up your car before you leave home

The first step to prevent foggy car windows is to turn the heat on inside your vehicle before you leave home. Not only will this make your trip to work more comfortable in the wintertime, but by turning the heat on early, you will also balance out your window temperature, which fights fog. If you choose to go with this method, turn the heat up on your car in full to dry out as much water and moisture in the air as possible. In addition, make sure that the air recirculation function is off, as this can actually result in more condensation.

Switch between your heater or air conditioner

The second way to eliminate foggy windows is to switch back and forth between your heater and your air conditioner. Start by employing the tip above, i.e. turning on your car’s heater on full blast. This will draw out as much moisture as possible. Next, turn off the heat and turn on your air conditioner for a few minutes. The AC will pull the last of the moisture from the air. Alternatively, if the air outside your car is dryer than it is inside your vehicle, you might be able to roll down your windows for a few minutes rather than turn the AC on. Either way, once your car windows are sufficiently warm, turn off your AC or roll your windows back up and turn the heater back on.

Reduce the moisture inside your car

Tip number three is to reduce the moisture inside your car. You may not even realize the different ways that moisture can enter a car. For example, if you have snow or rain on your clothes or shoes, this can turn into condensation once inside your vehicle. So take care to knock the snow and ice off your boots or wipe down a wet coat before getting into your car. Meanwhile, if you’ve got a wet umbrella or a towel that you used to wipe yourself off, put it in the trunk rather than throwing it onto the backseat or putting it on the floor of your car.

Otherwise, this extra moisture will likely make its way to your windows and fog them up. One other way to reduce the humidity inside your car is to remove all cups or containers with liquids inside of them. Letting an old water bottle or cup of coffee sit in your car for days or weeks on end can increase condensation, as over time, the liquid will start to evaporate. So do your best to throw away any old beverages or get into the habit of taking them into the house with you at night.

Try an anti-fogger

An anti-fogger is another effective tool that many drivers utilize to fight fogged-up windows. Anti-foggers or anti-fog agents are chemical treatments that coat your windows so that moisture doesn’t stick to the glass. They can also keep windows clear of dirt, oil, and other residue. When applying an anti-fog treatment to your car, be sure to use a microfibre or lint-free cloth. It is generally recommended that these types of treatments be applied just before winter sets in.

Clean your windows regularly

Cleaning your windows regularly is also important if you want to avoid the outcome of a foggy windshield. Plus, clean windows help increase visibility, which is important in other circumstances too, such as when you’re driving at night or in inclement weather. When you clean your windows, you are not only clearing off dirt, grime, and dust, but you are also minimizing the odds of fogged-up windows.

This is because when your windows are covered in dirt, condensation has an easier time sticking or clinging to them. The good news is that cleaning car windows is easy. Any household window cleaners will work. Make sure to dry them after cleaning. Experts recommend cleaning your windows at least once a week or more often in winter.

Keep a towel in your car

In a pickle, a towel can be used to wipe down the moisture on your windows and reduce fog. Find a small, lint-free cloth and keep it in your glove compartment. This way, if you need a quick fix, you have something at your disposal. After using a towel or cloth, make sure that you stow it in the trunk to avoid the moisture ending back up in your car.

Install a dehumidifier in your car

Installing a dehumidifier in your car may also help you prevent foggy car windows. Dehumidifiers are common household items but can also be used in vehicles. They work to absorb moisture from the air and work even better in small spaces, such as cars. If you opt to install a dehumidifier in your car, it’s best used in the morning. If a traditional dehumidifier isn’t right for you, there are also dehumidifying boxes on the market.

These boxes contain silica gel beads and trap moisture inside of them. They don’t need to be plugged in, unlike traditional dehumidifiers, and they can be left in your car overnight to reduce condensation build-up in the morning.

Repairs leaks immediately

Moisture can enter cars in various ways, one of them through leaks. If you suspect any type of leak in your car, you must take your vehicle to a mechanic and get it repaired as quickly as possible. Even if your mechanic says that the leak is minor, it can still wreak havoc on your car - and fogging up the windows is likely to be the least of it. Plus, there’s always a possibility that a small leak can turn into a big leak over time, causing further damage to your car and resulting in a costly repair.

Get in touch with BrokerLink

If you want more tips on how to clear up foggy car windows, reach out to BrokerLink today. We are auto experts who can provide everything from tips on how to de-fog your car to an explanation of the penalties for distracted driving. As an insurance brokerage, we can also help you find an insurance policy that meets your needs.

For example, in Canada, there are many types of auto insurance, including but not limited to:

We can help you find any of these coverages and more. Contact BrokerLink today to request a free car insurance quote from one of our licensed insurance brokers!

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