How to defrost car windows: the best ways to de-ice and demist windscreen quickly - and why ice forms inside

How to stop ice and condensation forming on your car windows

The weather in the UK has well and truly turned, with large areas experiencing prolonged sub-zero temperatures and forecasts for more snow and ice.

That makes for tricky conditions on the roads but also brings the eternal issue of iced-over windscreens before drivers even get going.

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It might be a cold and boring task but it’s important that you clear your windscreen properly to keep yoursefl and others safe and avoid a fine.

So here are our tips on the quickest way to clear ice, snow and condensation from your car windows.

Power up and use air con

Heating your car will help clear ice from the windscreen more quickly, so start the engine and get the ventilation working in your favour.

Remember to check your wipers are off before you start the engine. Activating them when they’re frozen to the glass could damage the blades or motor.

Use your heated rear windscreen and, if you’re lucky enough to have them, make sure your heated mirrors and front screen are activated as well.

Set your heating to blow warm air onto the windows to heat the glass from inside. Don’t use air recirculation as this will trap damp air in the car and cause condensation. Instead draw fresh air from outside and, if you have it, make sure your air conditioning is switched on. Air con doesn’t just help cool the car in summer, it can help to remove moisture from the air in winter, stopping your windows from fogging up as you clear the outside ice.

Clear loose snow

If it has snowed, use a soft brush or similar to clear loose snow from the glass, lights, number plate and body panels. Removing snow from the window will help melt the ice quicker, while removing it from everywhere else will help you comply with laws about visibility and causing a hazard to other drivers.

Use the right tools

It’s tempting when you’re in a hurry to grab whatever comes to hand to clear your windscreen. Credit cards and CD cases are perennial favorites but are nowhere as effective as a proper ice scraper. They don’t work as well as a purpose-made scraper and also run a risk of breaking in your hand or even scratching the glass. Using your bare hands is also ill-advised as any rings or other jewellery have the potential to damage the glass.

The same goes for clearing ice or condensation from the inside of the screen. Use a microfibre cloth rather than your bare hands as this will avoid damaging the glass or creating streaks that could affect your vision.

Use a de-icer spray

r sprays are a very quick way to cut through windscreen frost but that’s because they’re full of chemicals that aren’t particularly good for your car’s paintwork or the environment. Pre-made ones are handy if you’re in a hurry but you can also make up your own by mixing one part water to two parts rubbing alcohol or white vinegar.

Don’t use hot water

It really shouldn’t need repeated but don’t ever feel tempted to just chuck a load of hot water over your car windows.

The sudden shock change in temperature could crack or shatter the glass, especially if there’s an existing scratch or chip.

Even if that doesn’t happen, if the temperature is particularly low the extra water could just freeze again, creating even more work for you.

How to stop a car windscreen from icing up

Of course, better than any of these solutions is to prevent your car’s windows from frosting up in the first place.

The easiest answer is that if you have a garage, use it. Even a carport or other external shelter will offer a little protection from the worst of the weather and mean that, even if you still have to de-ice your car, it should be a little easier.

If that’s not an option, use a windscreen cover. You can buy purpose-made ones that will sit snugly over your windscreen or you can make one. A large towel, blanket or even sheet of cardboard will do, soaked in salt water and held in place by the windscreen wipers. Newspaper shouldn’t be used as it’s too thin and will simply stick to the glass.

You can also spray your windscreen with the de-icing water/alcohol solution in the evening, which should help prevent ice from forming on the glass.

Ice on the inside of a windscreen

In some extreme cases you might find ice has formed on the inside of your car’s windows.

This happens when the temperature drops so low that the moisture in the air - which would usually create condensation - freezes on the glass.

To stop this happening, make sure all your doors and windows are fully closed and remove anything that adds moisture to the car, such as damp shoes or clothes.

You can also reduce the risk by cleaning the glass, removing the microscopic pieces of dirt which the moisture clings to.

In addition, you can try rubbing a small amount of shaving foam onto the glass then buffing it off. This helps create a see-through barrier that stops the moisture sticking to the glass.