To clear steamed-up car windows fast, turn on the air conditioning, switch from recirculation to fresh air and point the demister at the windscreen. To stop them steaming up again, cut the moisture in the cabin and keep the inside of the glass clean with a glass cleaner such as CarPro Clarify and a dedicated cloth like the FibreKing Gold Label Korean Glass Cloths.
Why do car windows steam up?
Condensation forms when warm, moist air inside the car meets glass that is colder than it is. The moisture comes from the people in the car, from wet coats, shoes, umbrellas and dogs, and from any water getting in, so it is worst on cold, wet mornings with a full car.
When the air inside is not being swapped for fresh air, the moisture has nowhere to go and settles on the coldest surface: the windows.
How do you demist car windows quickly?
Use the air conditioning, because it is the most efficient way to take moisture out of the air, and let fresh air in rather than recirculating the damp air already inside. Then send that air across the glass.
- Start the engine or power up: the climate system needs the car running or switched on to work.
- Turn on the air conditioning: it dries the air, even with the temperature turned up for comfort.
- Switch off recirculation: select fresh air from outside so damp cabin air is pushed out.
- Use the windscreen demister: it blows air straight across the glass to clear it quickly.
- Clear the rear window: switch on the heated rear window if your car has one.
- Wait until every window is clear: you must be able to see out of every window before you set off, so do not drive away peering through a small cleared patch.
How do you stop car windows steaming up?
Reduce the moisture in the cabin and keep the inside of the glass clean. Clean glass steams up less readily, and a dry cabin gives condensation less water to work with.
- Do not leave wet things in the car: wet coats, towels, umbrellas and muddy mats add moisture every time the car warms up and cools down.
- Let fresh air in: avoid driving on recirculation for long periods, which keeps the damp air inside.
- Check for damp carpets: lift the mats and feel the carpet. Water getting in keeps feeding the problem until the leak is fixed.
- Use a moisture absorber: a bag of silica gel on the dashboard soaks up some of the moisture in the cabin when the car is parked.
- Clean the inside of the glass: a greasy film on the inside of the windscreen steams up more easily than clean glass.
If damp carpets have left the car smelling musty, our guide to getting rid of car smells explains how to dry and treat them.
How do you clean the inside of a windscreen?
Use a dedicated glass cleaner and two clean glass cloths: one to clean, one to buff dry. Spray the cleaner onto the cloth, not the glass, so it does not run onto the dashboard, and use the back of your hand to reach into the bottom corners.
These are the glass cleaners and cloths we use inside the car:
A dedicated glass cleaner for traffic film, oils, fingerprints and dirt, inside and outside the glass, that does not harm a hydrophobic glass coating.
Dodo Juice Clearly Menthol Glass Cleaner
A solvent-based automotive glass cleaner that leaves glass streak-free when used sparingly and buffed with a dry side of the cloth.
Stjarnagloss Glas Professional Glass Cleaner
A solvent-based cleaner for glass and clear plastics. Spray a small amount, wipe, then keep buffing until the glass is clear.
FibreKing Gold Label Korean Glass Cloths
Pile-free 40 x 40cm cloths with a thin sponge layer, in packs of three, that lift moisture, dust and fingerprints without leaving lint.
FibreKing Waffle Weave Glass Towels
300 GSM, lint-free and able to absorb up to eight times their own weight in water, which makes them useful for mopping condensation off the glass.
Our guide to cleaning car windows without streaks covers the full technique, and if the windscreen smears when the wipers run, read why a windscreen smears.
Our guide to cleaning a car interior covers the rest of the cabin.
Is it illegal to drive with steamed-up windows?
Yes, if you cannot see properly. You must be able to see out of all your windows before you drive, with the windows demisted thoroughly and the mirrors clear, so wait until the glass is clear rather than wiping a small hole to look through.
Common questions
Should you use hot or cold air to demist a windscreen?
What matters most is dry air. Turn the air conditioning on, because it removes moisture, and set the temperature wherever you are comfortable. Warm, dry air clears the glass and keeps it clear.
Why do my windows steam up when it rains?
Rain brings wet clothes, shoes and umbrellas into the car, and the cold outside cools the glass, so the cabin air gets wetter while the windows get colder. Fresh air and the air conditioning deal with both.
Why do my car windows steam up overnight?
Moisture trapped in the cabin condenses on the glass as the car cools down. Look for wet items left inside, damp carpets or a leak, and keep a moisture absorber in the car during the colder months.
Can you wipe the windscreen with your hand?
We would not. Your hand or sleeve leaves greasy smears that make the glass fog up more easily. Keep a clean, dry glass cloth in the door pocket instead, and use the air conditioning to clear the glass properly.
Need help choosing?
Tell the TDHQ team what car you drive and what the glass is doing, and we will suggest the right cleaner and cloths. You can also browse our glass care range and our glass and interior cloths.
