Why do car windows fog up inside and how can you clear them quickly?
Car windows can fog up quickly in cool, damp weather. The usual cause is moisture inside the cabin: passengers’ breath...
Car windows can fog up quickly in cool, damp weather. The usual cause is moisture inside the cabin: passengers’ breath, wet clothes and shoes, or snow brought in on the floor mats. When warm, moist air meets cold glass, tiny water droplets form on its surface.
How to clear fogged-up windows quickly
- Direct the airflow towards the windscreen. Select the windscreen demist or defrost setting.
- Switch to fresh air. Air recirculation keeps moist air inside the cabin and can make the fogging worse.
- Turn on the air conditioning, if available. Air conditioning helps remove moisture from the air. Set a comfortable warm temperature and use a sufficiently strong fan setting.
- Switch on the rear window heater. If your car has heated side mirrors, use that function too.
Do not set off until visibility is clear and the windows are demisted. If you need to wipe the inside of the glass, use a clean microfibre cloth and do so only when the car is safely parked.
How to prevent windows from fogging up
Brush snow off your shoes and avoid leaving wet clothes or other damp items in the car. Dry the floor mats when possible. Keeping the inside of the glass clean can also help reduce fogging and make it easier to clear.
If the windows fog up frequently even in dry weather, check the cabin air filter and make sure the ventilation system is working properly. Climate-control buttons and settings vary between vehicles, so consult the owner’s manual if needed.
