How to Defog Car Windows in Rain Without AC


Defogging a car window seems simple enough but it can become a little more complicated when your car’s air conditioning isn’t working. There are ways to defog your windows when air conditioning isn’t available even if it’s raining. 

The easy solution to how to defog car windows in rain without ac is to allow warm air to blow across the window while lowering your windows enough to balance out the inside cabin temperature. This can also be slightly problematic in the rain but if you lower the windows only slightly, you can keep rain from coming in. 

However, some of the best solutions to prevent fog on windows during any type of weather are preventive measures. Things like anti-fog products, good windshield wipers, and even shaving cream can be helpful.

More information about this topic can be found in the article below.

When Do Windows Fog the Most?

Car windows tend to fog during two types of weather conditions. They can fog when it’s muggy or raining, which can happen in the spring, summer, or fall. Windows can also fog during the winter when it’s cold and dry outside. 

The fog happens when the moisture on the outside of the window condenses. That happens when the window’s inside is colder than the cabin temperature. This is what causes a foggy window. 

The difference is summer and winter fog is that window fog tends to be on the outside of the window during warmer weather and on the inside of the window during colder weather.

Your window can collect fog on the outside by going through a foggy area, which tends to happen in the spring during the early morning or late evening hours.

Windshield wipers can be used to clean this type of fog away.

Keeping a fog-free windshield is an important safety issue because fog can affect your vision of the road. Some fog can cause additional glare, especially when a car with headlights approached you. 

There are things you can do not only to start without fog while driving but prevent fog from settling on your windshield with preventive measures.

Most ways you can eliminate fog without using your air conditioning are pretty simple and the preventive measures are things anyone can afford and do themselves.

Read: Can You Jumpstart a Car In The Rain?

What You Should Do

The first move for many drivers is to hit the defroster with the hottest temperature and blower available whenever you have fog on your windshield. However, that doesn’t work on foggy windows but works well on icy windows. 

This method will only make foggy windows worse whether the fog is on the outside or the inside of the window.

Foggy windows require you to balance the warm inside air with the window temperature. That would mean cooler air like an air conditioner, particularly in the spring and summer seasons, hitting the windows. However, you can get past that by blowing neutral or warm air across the windshield through the vents on the dash. 

It works quicker and best if you can roll down the windows while doing this. However, you can’t do that in the rain because the inside of the car, and you, will get soaked.

Instead, roll all the windows down about an inch to balance the temperature yet keep the rain out. Rolling windows down any further will allow too much rain to come into the car. 

The neutral or warm air will work during any time of year even though most assume you need cool air during the spring and summer months to correct a fogging issue. 

One key factor is to make sure the recirculating air button is off and that the fresh air button is on. You want fresh air to come through the air vents onto the windows. 

This brings the temperature of the outside air in and will help defog the windows faster.

Another important tip is to use your windshield wipers, as stated earlier. This can remove a lot of condensation from the outside during the summer months and will easily clear colder, icy windows in the winter once the defroster starts melting any ice.

If it’s raining, you will want to use the windshield wipers anyway so they serve two purposes. Just flip them on before you start driving to remove the fog during the summer.

Read: Why Won’t My Windshield Washer Fluid Come Out?

What You Shouldn’t Do

Your instinct, if you are in a hurry, is to rub away the fog with your hands. Experts say that is the one thing you shouldn’t do. 

Oils from your hands will transfer to the window and that will cause smears preventing you from seeing properly while driving. It will also make a later fogging problem worse later on. 

A good tip is to put a microfiber cloth in your car so you can use it to wipe down your windshield if you are in a hurry. 

These cloths are available anywhere but the ones that are heavily threaded and contain silver work the best.  They absorb moisture the best and leave your window streak-free.

Some will even naturally disinfect your car if they contain silver. Silver attracts bacteria and removes it from your car’s surface.

Using Anti-Fog Products

There are many anti-fog products on the market and many work reasonably well. The ones worth investing in are windshield wipers that keep the rain off your windshield. 

This product works incredibly well to make your windshield rain resistant. They work well to keep your window clear of fog too.

Experts recommend to not spray anti-fogging sprays directly on your window because they can splash on your dash and in your vents. The proper way to apply them is to spray them on the microfiber cloth and then wipe the window down with the cloth. 

Watch which products you use on your windshield. While they are effective, some products diffuse the light and can cause glare at night. 

A silica ball left inside your car is a cheap way to absorb moisture. Put one or several in a stocking or sock and leave in your car.

Other Preventive Measures

One car owner offers a tip on how to keep windows from continuously fogging up. They suggest cleaning the inside of your windows with cheap foaming shaving cream and a soft cloth. 

Spread the shaving cream on the inside of your windows and leave for two minutes. Take a soft cloth and wipe it off as much as possible.

Use a separate clean cloth to wipe it dry. Windows will not fog up afterward for quite a while. The best cloths to use are high-quality microfiber cloths. 

Another expert tip is to keep your window clean. Clean windows tend to fog less often. A dirty windshield is harder to see out of when it’s foggy because there tends to be a lot of glare from the dirt.


Getting rid of fog on car windows with air conditioning, particularly in the rain, may take some thought but isn’t an impossible task. The secret lies in achieving a temperature balance. 

Preventive measures cost little to implement and could make life with your car a lot easier as they prevent fog from accumulating in the first place.

Read: Temperature Gauge High But Car Is Not Overheating

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