Car windscreen freezing inside? Here’s how to fix it fast

Driving in winter is tough, especially when your car windscreen is frozen not just on the outside, but also on the inside. Here’s how you can prevent it and what to do if it happens anyway.

The chilly, wintry weather in the UK is now upon us. This means your car is likely to be covered in ice more often, which can add an extra ten minutes to your morning routine as you clear your vehicle’s windows.

Most car owners have experienced a frozen windshield on the outside and know how to deal with it. But ice forming on the inside of your windows is a different challenge.

In this guide, we’ll explain why it happens, how to prevent it, and what to do if your car windows freeze on the inside.

Remember, you can buy a brand new or used car right here on Carwow. And you can sell your car, too. We’re here to help you through every step of your car-changing journey.

Why do car windows freeze on the inside?

The answer is: humidity – and we’re largely to blame. While driving, our breath adds moisture to the air inside the car, which condenses on the windows. In the summer, it’s barely noticeable, but in colder temperatures, the condensation freezes.

Cold air holds less moisture than warm air, but if you heat your car a lot in winter and there’s extra moisture outside from rain or snow, the car can quickly become overly humid, leading to frozen interior windows the next day.

It’s also worth noting that if you have a motorhome, try to avoid high humidity when prepping it for winter, as this can encourage the growth of mould. Excess moisture in a car can also lead to rust.

What to do when a windscreen is frozen inside

If the windscreen is frozen on the inside, the best approach is the three-step method: ventilate, scrape, wipe.

1. Ventilate the car

The first step against icy windows is to ventilate. Open all the doors for a few minutes and let the car air out completely. This allows the humidity inside to escape, while the cold outside air absorbs the moisture.

2. Scrape the windscreen; turn on the heater if needed

If ventilation alone wasn’t enough, see if you can scrape the ice from inside of the windscreen. But do bear in mind that not every ice scraper works for this, because the curve of the glass can make scraping from the inside a bit tricky.

To make scraping ice easier, you can also switch on the blower and direct vents towards the windscreen. It will take a little while for the engine to warm up enough to blow warm air onto the glass. This does mean idling your car, though, which isn’t particularly eco-friendly and is illegal. However, you could consider a parking heater.

3. Wipe away condensation

Once the windscreen is clear, but sure to wipe away any melted ice water from the dashboard and glass. Also don’t leave wet cloths inside the car, because the moisture will redeposit and the cycle will begin again.

How to stop the windscreen from freezing inside

An internally frozen car is incredibly annoying and time-consuming to fix, so it’s best to prevent it entirely. Here are a few precautions you can take:

• Ventilate the car briefly after every drive or open the windows slightly while driving.
• Avoid bringing snow or moisture into the car.
• Turn on the air conditioning even in winter.
• If you’re wet from a winter walk or have snow-covered shoes, bring a change of clothes or shake off wet items before entering the car.
• Remove wet floor mats overnight and store them in your home or garage.
• Place a car dehumidifier near the windscreen as this will help absorb the moisture in the car. Homemade solutions can also work – for instance, you can put cat litter into a permeable container, such as an old sock or fabric bag.
• Newspapers can be laid out in the footwell and replaced daily to help absorb the moisture.

Top tips: Test your car battery from time to time, as weak batteries can cause problems, especially in winter. Also check your door seals and sunroof for leaks regularly as this can also bring moisture into the car which leads to humidity.

What NOT to do on frozen interior windows

Some methods are dangerous for both the car and people and should never be used to clear ice on the inside of your car. Here’s what to avoid:

De-icing spray is a no-go

Never spray de-icer on the inside of a window. It’s helpful on the outside, but in a closed space it can be hazardous to your health. It also smells rather unpleasant.

Stay away from high heat

Strong heat sources such as candles, matches, or hot air guns should not be used inside or outside to de-ice. They create a very hot spot, while the glass remains very cold, which can cause the windscreen to crack.

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Looking for a new set of wheels? With Carwow you can sell your car quickly and for a fair price – as well as find great offers on your next one. Whether you’re looking to buy a car brand new, are after something used or you want to explore car leasing options, Carwow is your one stop shop for new car deals.

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