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How to remove condensation inside a car

Do you find you get a lot of condensation inside your car? You’re not alone. Our handy guide will tell you what can cause it, what to do to get rid of it and how to prevent it from happening again.


Do you find you get a lot of condensation inside your car? You’re not alone. Our handy guide will tell you what can cause it, what to do to get rid of it and how to prevent it from happening again.


Written by
Rory Reid
Car and technology expert
Last Updated
25 JUNE 2024
7 min read
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What causes condensation in my car?

Condensation inside your car is caused when the warm air inside meets cooler air from the outside – via a windscreen, for example – which condenses to create moisture.

Steam can also be a culprit for condensation in cars. If there’s liquid inside your car and the sun then heats the interior, the rising steam collects on the surfaces as condensation.

There are a few other causes of condensation in cars, including:

  • Breath from passengers in cold weather
  • Leaks from doors, windows, the sunroof or vents
  • Steam from hot drinks and food
  • Coolant leaks.

Do new cars have less condensation?

Not necessarily. Newer cars have better seals and insulation, which you’d think would work in their favour. But when it comes to condensation inside cars, trapping warmer air inside more efficiently can actually lead to a build-up of moisture.

To counteract this, crack a window open and introduce airflow whenever you can.

How do I stop condensation in my car?

To prevent condensation inside your car, there are a few simple steps you can take to help keep moisture at bay.

Don’t leave wet items in your car

If you got caught in a downpour and left your coat on the back seat, take it with you when you park up at the end of the day.      

Umbrellas, raincoats, damp gym kits or the dog blanket can all cause humidity in your car, which may lead to condensation.

Keep the windows open when you have hot food or drinks

Having a quick bite to eat or morning coffee when parked in your car is handy. But the steam from warm food and drinks can cause condensation inside cars.

If you’re not able to keep the windows open while you eat or drink, turn the air conditioning on to suck out that extra moisture.

Keep your car covered overnight

If you keep your car in a garage, a lightweight, breathable cover could help prevent condensation inside your car when parked. If you have a serious moisture problem, you could use a dehumidifier or a low-powered heater to keep the air dry.

If you’re keeping your car locked up for long periods, remember to take it for a drive regularly. This will keep everything ticking over and give it a blast of fresh air, as well as stopping your car battery from going flat.

For more on keeping your car in a garage and the possible impact on your car insurance, see our overnight parking guide.

Ventilate your car regularly

It sounds simple, but keeping the windows ajar on hot days and closing them on wet days will help keep your car dry.

In the winter, you could turn on your air conditioning – even while the heating is on. The AC system draws the air from the inside of your car through an evaporator, which condenses moisture and allows it to drain off outside.

Keep your car windows clean

Condensation sticks to dirt and grime, so keep the inside of your windscreen and windows clean.

Watch out for leaks

If you’re consistently noticing a lot of condensation inside your car, you might have a leak. Leaks in the door seals, boot or sunroof could allow rainwater to seep in and cause areas of damp.

The heater matrix (the mini radiator that warms the inside of the car using heat from the car's cooling system) is another common culprit when it comes to leaks.

If you do suspect a leak is causing condensation inside your car, it’s worth speaking to a professional to have it fixed.

Use your car’s climate controls

There are two settings on your car’s climate controls – ‘recirculate’ or ‘fresh air’. By switching your climate controls to ‘fresh air’ mode, you’ll ventilate your car by bringing in air from the outside.

How to clear away condensation from your car windscreen and other windows

If you find your windows all fogged up in the mornings, you’ll need to clear away the condensation before you drive. If you can’t see out of your windscreen properly, you can’t drive safely – or legally.

Here’s how to clear condensation from your car windscreen so you can get on your way:

  1. Turn the heater on to the cool setting, using the windscreen option if you have one
  2. Switch on your air conditioning to get the air circulating. If you don’t have AC, open the windows
  3. Gradually turn up the heater as the condensation begins to clear
  4. If your car has one, turn on the windscreen and rear window heater or demister to help speed it along.

How to dehumidify a car and remove damp

If a lot of moisture has built up inside your car, you’ll need to dry it out to avoid problems with condensation and mould in the future. Here are some tips on how to dehumidify your car:

Air out your vehicle

The best way to remove damp and prevent mould in your car is to ventilate it. If it’s a mild day with no chance of rain, open the windows and doors for as long as you can. Just remember not to leave your vehicle unattended.

If moisture appears while you’re driving, crack a window open if it’s dry outside or turn on the air conditioning if it’s raining.

Remove excess moisture from your car

Remove any excess moisture from damp surfaces in your car with a dry cloth. You might also want to try using a fan or hairdryer to dry the upholstery if it’s damp.

Use a car dehumidifier bag

You can buy dehumidifiers, which are bags filled with silica gel that sit on your dashboard and absorb moisture. These packs can be reused by microwaving them to remove the moisture.

How to get rid of mould in your car

If you have mould inside your car, you’ll want to get rid of it as quickly as possible. Not only does it look and smell bad, but it could also have negative effects on your health.

Luckily, you can get rid of mould inside your car with just a few household items and some elbow grease.

It might be a good idea to wear rubber gloves and a mask to make sure you don’t breathe in any mould spores while you’re cleaning. Here’s what to do:

  1. Start by cleaning out your car. Remove any rubbish and belongings from the inside and throw away anything that looks mouldy.
  2. Vacuum the carpets, car seats and any other upholstery to remove any mould spores.
  3. Fill a spray bottle with a mix of eight parts distilled white vinegar to two parts water. White vinegar removes mould and could prevent it from coming back. You can also use diluted clove oil, a diluted baking soda solution or a specialist cleaning product.
  4. Spray the vinegar solution onto any mouldy surfaces or upholstery. Saturate these areas, using a scrub brush to work the solution in. You may want to test a small amount of the solution first on an area that’s out of sight.
  5. Air out your car to help remove the vinegar smell. Once it’s dry you can apply baking powder to any areas you’ve treated and then hoover it up.

What causes mould in cars?

Damp and poor air circulation are the main causes of mould in cars. To prevent mould recurring in the future, follow our tips above on how to prevent condensation from forming. Also, remember to dehumidify your car regularly.

If there’s a bigger problem, like a leak causing damp in your car, you’ll need to have this fixed to keep the mould at bay.

Does having damp in my car affect my insurance?

Possibly, yes. If you had an accident when your vision was impaired by condensation your insurance could be affected.

Check out the common issues that lead to car breakdowns.

Frequently asked questions

Why is my car wet inside?

If you’ve ruled out condensation, there are several other reasons why your car could be wet inside.

Maybe you left the window ajar and it started raining, the sunroof might have leaked or a door seal could have gone. Or perhaps one of the kids spilled something on the back seat and didn’t tell you.

Once you’ve got to the root of the problem, it should be relatively easy to fix it.

How do I stop condensation in a van?

If you use your van a lot and condensation is a persistent problem, consider a dehumidifier or low-powered heater to dry it out. Keep windows free of dirt and grime and check for leaks if you spot damp patches. You could also install window covers as an extra measure.

If you’re a camper, make sure you’re not storing damp equipment in your van. Be sure to keep any cupboards open when the van’s not in use, too.

If you leave your van in storage for long periods, try to visit regularly to air it out and keep everything in working order.

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Rory Reid - car and technology expert

Rory Reid is a car and technology expert. He serves as the main presenter on Auto Trader’s YouTube channel and was previously a host on BBC Top Gear and its sister show Extra Gear. He is also a presenter on Fifth Gear. Previously, he hosted Sky TV’s Gadget Geeks, CNET’s Car Tech channel, BBC Radio 5 Live’s Saturday Edition and on the YouTube channel Fast, Furious & Funny.

Learn more about Rory

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