How to demist windscreens in cars

It’s a familiar scene across the UK – getting into your car on a frosty morning, possibly already late for work, ready to get on the road, only to be delayed as your normally pristine windscreen suddenly becomes completely opaque.

This is, obviously, very aggravating; especially if you’re not fully prepared to deal with the rising fog clinging to your windscreen, no matter how many times you try to wipe it away with the sleeve of your shirt/hoodie/jacket. Luckily for you, we’re here to explain the best ways to demist your windscreen in a timely and effective manner.

Why demisting car windscreens is important

I’m sure this doesn’t need to be said, but just for absolute clarity (that is, after all, the point of this article), you can’t drive if you can’t see out of your windscreen.

It’s important to remember that you need all your windows to be clear before moving off. The more windows are blocked, the more blind spots you have, the more likely you are to have an accident.

Why does my car steam up?

It’s a question we all ask ourselves at one point or another in our driving careers – why is it fogging up now?

You’ll be happy to hear that it’s actually very easy to predict how and when a screen will fog up, and there are a number of different ways to prevent it from happening in the first place.

A window fogs up due to condensation. As warm water vapour, found naturally in the air, makes contact with the very cold glass of the windscreen, the vapour condenses, turning into liquid water and blocking your view of oncoming traffic.

This means there are two key factors you need to think about when it comes to demisting your vehicle. The first is how cold it is. The colder the day, the colder your windscreen, making it much more attractive to warm vapour.

The second is how much moisture there is in the air – depending on where you live, this can be a huge variable. This is why, even when it is technically colder, your windscreen is more likely to mist up on damp chilly days rather than a crisp cold morning.

So, if you want to keep your windscreen mist free, keep your windscreen warm and remove water vapour from your car’s interior.

How to get rid of condensation inside a car windshield

Knowing why it’s misting up doesn’t always help – after all, we can’t exactly control the weather. So, if your screen starts to mist up, here are the best ways to deal with it quickly so you can get back to driving.

Heater on

The first and most obvious option is to blast your car’s heaters on full. Almost all modern cars have the option to aim your heater’s warm air directly onto the windscreen, and this is one of the most effective ways to demist your front windscreen, as a warm windscreen means no condensation.

Air conditioning

Another tip that makes use of your car’s climate control is to turn on your air conditioning. Using your air conditioning naturally removes water vapour from your car’s interior, and so stops your windows from misting up. This has the added benefit of demisting not just your front windscreen, but all windows in your car – though making your vehicle’s interior cold on a winter’s day might be a bit much for some!

Windows open

Of course, not every car has air conditioning, but don’t worry, there are still some great options to demist your windscreen without a heater or air con.

One method is simply to open your windows. Generally (again, depends on where you live), the air outside your car will be drier than the air inside, so having a good flow of air will help remove unwanted water vapour.

Step outside

Another effective way to help demist your car, though only if you’re not currently driving of course, is to open the door and step outside for a minute. Did you know that water vapour inside your car mainly comes from your breath? Removing yourself from the car for a short time can prevent any more moisture gathering inside the car.

Dehumidifier

It’s not always possible to open a window or to step outside. For one thing, those tips only work if it is, in fact, dry outside and not pouring with rain. So, the question becomes, how to stop car windows steaming up in rain?

Well, if you live in a wetter climate and find your car is constantly fogging up, you can invest in a car dehumidifier – there is a great selection available, and they can be particularly useful for older models which suffer more from the damp thanks to delicate trims and electronics.

If you don’t want to spend too much, there is always the option of hanging up a sock that has been filled with kitty litter… but it’s not one we would recommend!

A good micro cloth

For an immediate effect, a good microfibre cloth is a great option to wipe clear a window. Keep in mind that unless you deal with the root cause of the misting, it will very quickly fog up again, possibly at an inconvenient time on the road.

Your best bet, even if you’ve wiped your windscreen clear, is to take that little bit longer to make sure that your windscreen has warmed up or that you’ve dealt with the excess water vapour in your car before setting off on your journey.

Shaving foam?

There is an old wives’ tale that applying shaving foam to your windscreen will protect it from misting up. We haven’t had the weather yet to confirm if this works – though you are welcome to try it! Again, this isn’t one we would recommend but if you are feeling adventurous…

First, clean your window, then apply shaving foam, and finally wipe the shaving foam off; allegedly, your screen will now have a protective layer covering it and stopping water vapour from reaching your windscreen. The only thing is that you will need to reapply the shaving foam from time to time for it to remain effective. You can always use branded products for a similar effect, but where’s the fun in that?

How to demist your back windscreen

If you want to quickly demist your back window, then the good news is that all the above tips work great for the back window as well. The only difference is that many cars have a back window demisting option.

This works by running electricity through very fine filaments in the glass itself (the black lines you can see). This gently warms the glass up and evaporates the water.

How to demist your wing mirrors

A slightly more difficult endeavour, a wing mirror misting up can be a real problem while you are driving – outside of our control, the wing mirrors are wholly dependent on the outside environment.

Thankfully, manufacturers are now including heated wing mirrors in newer models, a very effective way of keeping them crystal clear. Of course, you can always try the shaving foam hack on your wing mirrors as well.

Hopefully, this will help you in demisting your car quickly on those wintry mornings, but the absolute golden rule to keep in mind is this: make sure your windows are clear before driving off. It’s always worth taking a little bit longer to be safe on the road.