During winter here in Canada, my 2011 Cruze seems like it has humidity on the inside of the windshields. When I take a look at other cars besides mine, there is moisture on the exterior, not interior. Could I have a sealing problem on some joints on windows and windshields?

It's really annoying when the temperature changes suddenly creating a layer of thin ice like dust made with ice, inside.

What can I do about this?

  • 1
    So you have humidity on the inside or outside?
    – JPhi1618
    Commented Mar 26, 2018 at 16:14
  • 2
    Is the system set to recirculate? Or fresh air?
    – CharlieRB
    Commented Mar 26, 2018 at 16:51
  • 8
    Do you use the defroster? Does the A/C work? In most cars here in the States, when you put it on defrost, the A/C kicks on to dehumidify the interior of your vehicle, which prevents condensation from forming on the windshield and other glass areas. I'm assuming most cars are the same in Canada as they are here in the States. Commented Mar 26, 2018 at 17:18
  • 2
    Is it oily? Any smell?
    – George
    Commented Mar 26, 2018 at 22:29
  • 1
    A trick I heard of, which I've never tried so won't put it as an answer - a small gauze bag of cat litter to soak up the moisture in the car overnight. I think it has to be specific type, so just sawdust won't do it. :) Commented Mar 28, 2018 at 9:10

13 Answers 13


There is something (very) wet inside your car. Feel around the floor, look at all the lowest points of the floor. If the front passenger floor is wet check the hoses to the heater core. Check all window gaskets. Check the spare tire well and the trunk gaskets. Check to make sure that all windows roll up completely. A fold or tear in a gasket or debris can make it look like the window is closed when it's not.

How long has this been going on? Has your car been in an accident? Is your car always parked outdoors?

Sources for water are the cooling system and water from the external environment. There is water inside your car, you just need to find it and then figure out how it's getting in.

  • 2
    I'll second this. My old Focus had a leak in the windshield cowl and let water collect under the passenger floormat and caused the same problem the OP has.
    – Spivonious
    Commented Mar 26, 2018 at 18:30
  • 2
    A clog in the evaporator hose will also result in a lot of moisture accumulating inside the cabin when the AC/defog is running.
    – Ivan
    Commented Mar 27, 2018 at 17:07
  • 1
    Confused, can't the water come from air humidity too?
    – user541686
    Commented Mar 27, 2018 at 22:16
  • 1
    Canadian winter can be a frozen, bone-dry hell. It doesn't take much moisture to end up with internal condensation, nor is it particularly abnormal or alarming. I wouldn't say that there is necessarily anything "very wet" in the car, nor would I suspect a leaking cooling system in the first instance.
    – J...
    Commented Mar 28, 2018 at 13:20
  • 1
    My car gets foggy inside at times as well and it's never due to something wet. Usually condensation is to blame.
    – Mast
    Commented Mar 28, 2018 at 15:40

Do you use the circulate feature on your car? This should be turned off. It looks like the image below:

I learned early on that this causes this exact issue in the winter. My theory is that the moist warm air we breath out is circulated over and over and then sticks to the cold windows. When you shut that option off, you are pulling in fresh (dry) air from outside.

  • 2
    Thats odd, I had the exact opposite experience. Turning this feature on reduced humidity. My guess was that the A/C was filtering the humidity from the air instead of pulling new humidity in. But I agree, changing the options of the heating / AC can change things. Commented Mar 27, 2018 at 13:29
  • 1
    I think you have a problem with evaporator in your AC unit. The air humidity shall collect there and be drained away. By introducing cold ambient air "solves" your problem because it can carry much fewer water vapour than the warmer air inside the car.
    – Crowley
    Commented Mar 27, 2018 at 16:44
  • 1
    That's probably the answer - the wet thing inside the car is OP :) Commented Mar 28, 2018 at 6:27
  • 2
    Many cars will automatically turn on your AC when recirculate is on to prevent buildup of moisture, but not all. It's those others that could suffer from this, so if you want to use recirculate and avoid moisture build-up, also turn on your AC.
    – agweber
    Commented Mar 28, 2018 at 14:14
  • 2
    @AngeloFuchs When using the AC to cool the air, it does dry the air—as air blows over the cooling element the moisture condenses, outside the car. Recirculating under those conditions will dry the air more, because the same already-dried air is run through the process again. But when running the heater, the equation changes; now, the windows are much colder than the air, so if you don't somehow send the air outside of the car all the humidity created from evaporation of your sweat and the melted snow from your boots condenses when it hits the windows, creating fog.
    – 1006a
    Commented Mar 28, 2018 at 21:14

On my car the A/C is on all the time - as per the handbook, specifically to control the humidity inside the car.

You should consider running with the A/C on over the winter and see if that makes a difference.

  • I'll check this
    – CREM
    Commented Mar 26, 2018 at 18:20
  • So, Jaguar x-type and I can't get to the pdf handbook at the moment, but it does work...
    – Solar Mike
    Commented Mar 26, 2018 at 19:11
  • AC could be broke.
    – Mazura
    Commented Mar 28, 2018 at 19:52
  • @Mazura my a/c is fine...
    – Solar Mike
    Commented Mar 28, 2018 at 21:02
  • At a small cost to performance and economy.
    – Tim
    Commented Mar 29, 2018 at 14:44

One thing that helps to deal with fog inside the car is a humidity absorber: enter image description here

Of course, absorbers can only trap some residual humidity, so if you suspect there's a leak you should find it and fix it first.

  • 1
    Is this a huge bag of silica gel beads? Commented Mar 29, 2018 at 9:32
  • @user1306322 Yep. It's the kind you can dry in a microwave. Commented Mar 29, 2018 at 12:47
  • @user1306322: Probably. Except that, apparently, it's actually a fairly small bag of silica gel beads. Anyway, you could probably make your own cheaply by buying some silica gel (a.k.a. "crystal cat litter") and putting it in a cloth bag. Or an odd sock (great for drying wet boots, too). The Pingi brand one does seem to come with a moisture level indicator, though, which is a useful feature to have. Commented Mar 29, 2018 at 12:48
  • @IlmariKaronen Car litter is a different variety of silica gel designed to adsorb liquid (with bigger pores). It's not that good at adsorbing moisture. Of course, one can still save by buying bulk silica gen instead of a nicely packaged one. Commented Mar 29, 2018 at 12:53

I own a 2011 Cruze, live in a place of ice and snow, don't have a garage and experience the exact same issues I would suggest the following to mitigate...

  1. The moisture doesn't have to be from a leak, the snow off your shoes is plenty when evaporated by the heat. Getting the floor mats dry in the winter is almost impossible. I've found that if I knock my feet together a couple of times after I sit, but before I put my feet in the foot well helps a lot by not bringing snow into the car to begin with.

  2. Only use Recirculate until the car is up to temp, then switch to fresh air which is drier unless its raining or melting.

  3. Crack a rear window while driving. This may seem counter intuitive, but the extra draw (like wind across a chimney) and the fresh air flow will combine to pull more heat into the cab. Also, if you don't use the front defrost, it will keep your windshield colder and mean that ice builds up less on the blades since snow hitting the windshield will bounce off rather than melting on contact. (I've gone as far as mechanically blocking those vents, with a towel, since they seem to get heat all the time even when only floor is selected.)

  4. Clean the inside of your windshield. Particles on the surface provide additional places for water to condense. Optionally use something that repels water, but clean and not something that dirt would stick to is great.

  5. Change the cabin air filter located behind the glove box. Because the defrost vents seem to run all the time, a dirty cabin filter will spray that dust onto the glass as it is brought in from the outside.

  6. When you park, Roll down the windows to let out all the heat, and then roll them up leaving just a crack on one. Not so much that snow will fall in. you only need a sliver to let the remaining heat out with all the moisture that it has picked up from inside the car.

Regarding the AC. It does dehumidify the air, Dry air gives your sweat someplace to evaporate too, that makes you cooler. In the winter however, it is possible for the AC drain to freeze shut. Some cars have drains for the AC under the passenger floor pan. If the drain freezes the water you dehumidify will pool on the passenger floor making your problem worse. Other things can cause it to plug too, like dirt.


I get this if I take my landrover through a river crossing. There's moisture inside your car which condenses on the cool glass.

The fixes

  • Take all the carpets and soft items out to dry in the sunlight (but its winter)
  • Park inside a garage and put a dehumidifier sitting on a front seat. You can generally fit a mains power cable through the weather stripping at the rear of the door, or if that seems too tight you can run the mains cable through an open window, then close the window mostly, and seal around it with tape or plastic clingfilm. Run the dehumidifier overnight on high, not automatic.

The car will smell better too.

Another way to minimise this problem is to stop parking your car outside - the vehicle will start and run better if its garaged overnight with a window open for ventilation. More-so again if its cold and snowing outside.


I had a similar issue with a Holden Commodore and after several visits to multiple repairers, including a windshield replacer, learned that GM (Chevrolet, Holden, Opel, etc.) vehicles often have issues with door seals.

Chevrolet Cruze Door Jamb

The door seal is the rubber strip that seals between the door and door jamb. Often this fails due to extreme temperatures (heat in my Australian case, cold in your Canadian case) and allows rain into the inside of the vehicle. In my case, the passenger side floor was wet by the end of winter, a pool 5-10 cms deep formed in the rear floor area.

I first clued in that there was moisture in the car because of condensation on the interior of the windscreen. Feel the carpet under all seats, if it's wet, have you door seals replaced soon or like me your car will start growing mold.


We get this in reverse in Australia when there is a bit of humidity in the air on a hot day and we turn on the car AC. The conditions have to be right. We get small patches of blurry condensation on the outside of the glass which correspond to where the vents blast out the cold air on the inside of the windshield. Its the same effect as the condensation on a iced drink glass. It's just the natural moisture in the air cooling until it forms a liquid, unless there is a LOT spread of the blurry condensation effect its normal. Why other cars you've looked at don't do that could be due to them not using recycled air as JoelC mentioned already, or perhaps they have had their windshield treated with something. I can't remember what it is, but I believe there is a chemical which is supposed to mitigate that kind of condensation.


I own two cars, live in place with cold weather, continuously use the air conditioner and checked the floors for wetness- it's not (only) that.

An advice I've got from a local forum was to leave the doors opened for a few minutes when I get home, although it is not really convenient in cold weather it did work !

My theory is that I turn the heating too high, this causes humidity to build up in the car and later condensate on the windows.

Another factor that might help is keeping the windows clean from the inside, dust and oil help water condensate on the window.

  • OP said: other cars around him have no such problem. No chance all owners are ventilating for X minutes.
    – kubanczyk
    Commented Mar 27, 2018 at 10:05
  • NO chance, but I forgot to mention that I, and none of the cars around me, have this problem. I suspect it's because I use more heating in the car making it more humid.
    – Rsf
    Commented Mar 27, 2018 at 11:53

As mention the cause is usually down to a break in your door seals or a leak.

Sometimes the way in could be in the bulkhead ie the bit between your dashboard and the front compartment(usually where the engine is) as a lot of wires pass through.

Getting the carpets out can be a big job and drying the underlay can take sometime.

Whilst the carpets are out and you have dried the area use a bit of baby talcum powder to see where the leak is coming from.

I did watch an interesting youtube video (not mine) which might be of help to help against the condensation as a quick fix until the summer comes.



I had the exact same problem this winter with my Mazda R-X8, I could not find any leaks or issues with A/C so I resorted to buying Pingi's and they works like a charm. Hope you get it sorted I know how annoying it is.


Maybe the anti-fog coating on your car has lost its effectiveness (if it had any). Take this with a grain of salt since I don't really know anything about cars, but products like Rain-X might help.
Note that you might need to clean off any accumulated oils/dirt/etc. before using it... look up the application procedures; I don't know the details.

  • Note rainx has an antifog product in a black bottle, that is intended for the inside of the glass, and is different to their external product in the yellow bottle.
    – Criggie
    Commented Mar 28, 2018 at 12:50
  • I have used the black bottle Rain-X product - it is very effective at reducing fog on the inside of vehicle glass. OP should still try to find and resolve the source of the moisture, but even then, this is a great stop gap to let you see again while your car spends the next few days/weeks drying out (it can take a very long time in colder months).
    – CactusCake
    Commented Mar 28, 2018 at 13:40
  • I have used the product too, and it does work if you live in a warmer climate or garage the vehicle and have the issue. It is not very effective when the air is below freezing for months on end. Commented Mar 28, 2018 at 23:49

Another thing that could be causing your issue is when dirt particles attach themselves to the windscreen, it can exacerbate the condensation issue, so it is important that you clean the inside of your windscreen regularly. Using a car window cleaner and a microfibre cloth, give the inside of the windscreen a good clean.

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