How to Keep Your Car Windows From Fogging up in the Winter
Cold winter mornings can make driving just as tricky as a wet summer day, though instead of water on the outside of your windscreen affecting your ability to see the road ahead of you, it is moisture on the inside. Car windows fog up more frequently in winter because the glass is colder than the dewpoint inside the vehicle, leading to condensation. And knowing that helps us to take steps that will keep our car windows from fogging up, or to clear the fog faster.
Keep Your Car Windows Clean
If you don’t frequently travel with your pets or young children in your car, it is easy to forget to clean the inside of your car’s windscreen and other windows. And while they may look clean, they likely have a build-up of oil and dust on them, creating an excellent surface for moisture to adhere to and causing your windows to fog up much faster.
Try to get into the habit of cleaning the inside of your windscreen and other auto glass every time you wash your car, and more frequently in winter if you regularly find your windows fogging up. You can also try using an anti-fog treatment for interior glass.
Get Rid of Frost
If you have no choice but to park your car out in the open at night, invest in a windscreen shield to keep the windscreen clear of frost. The windows of your vehicle will already be cold because of being out in the open, but they will be less cold than if they were also iced up. And until you get the windscreen shield, make time to clear your windscreen – and the rear window too – of frost before driving anywhere. And you need to clear the entire windscreen, not just a section in front of the steering wheel.
The rear window should be equipped with a built-in defroster, and you should turn this on as soon as you start driving, even if you have cleared the glass of frost. The defroster will warm the glass, helping to keep it clear of moisture.
Keep Moisture Out
The more moisture there is inside your car, the greater the risk of the windows fogging up on cooler days. If you live in a winter rainfall area, or an area that gets some snow, invest in a car dehumidifier to help absorb moisture from the car’s interior. You might want to also get into the habit of kicking snow off your shoes before getting into the car and storing wet umbrellas and jackets in the boot of your car, especially on cold or cooler days when there is a greater risk of the car windows fogging up.
Use the Aircon
We have previously advised against using the heater in your car too soon on colder days, and that still stands as the sudden change in temperature can cause auto glass to crack. But the aircon, blowing cool air at first, can help warm the air up slightly – raising the dewpoint – and helping to circulate moisture out. Just make sure the recirculate function of your aircon is turned off, and that the vents are open.
Open a Window
Finally, if the fogging up is really bad, and none of the above is helping, you will need to open at least one window slightly to help circulate air, drawing in fresh air and allowing moisture out