Frost On Inside Of The Windshield? Find Out Why!

You’re the busy type, or not, and you wake up early in the morning, take a hot coffee, and get ready for work. Except you get to your car and discover it’s covered in ice. The insides of your windshield are also Frosty.

You could scrape the ice outside, but what about the frost on the inside windshield? What should you do? A quick warm-up of the car engine would eliminate the frost but only temporarily. Read this article to know the fastest and safest way to permanently eliminate frost throughout the winter to save your day.

Is it normal to have frost on the inside of the windshield?

It is perfectly normal to experience frost inside your windscreen or your car windows occasionally. Frost is water vapor turned solid or ice. You should know that not all countries experience frost. The sun’s rays are most potent in countries close to the equator line.

This is why snowfall is a rare occurrence in Africa. However, countries farther from the equator get a lot of frosts as the sun isn’t shining directly on them.

This would mean countries like the United States, Canada, Australia, and so forth. They experience cold temperatures, sometimes below the 0° degrees freezing point. Of course, having frost on the inside of your windshields all the time would be displeasing and undesirable. We usually only get frost during the cold seasons, autumn and winter.

For the USA, this would be from early September through December till February. It is uncommon to have frost during summer as the sun is always warmer. In other words, frost formation occurs routinely, mainly during the cold winters.

What is causing frost to form on the inside of the windshield?

Frost is simply water in gas form turned into ice. Moisture is always present in the air. And the amount of moisture or water vapor in the atmosphere is termed humidity.

Water vapor cools or condenses on the windscreen to form tiny water droplets called dew. If the temperature worsens, these droplets freeze to form icy crystals. These icy crystals are called frost.

Frost forms on a surface if the temperature of that surface is below or at the dew point, which is the freezing point of water; 32°F or 0°C. Again, the temperature has to go below the dew point; else, all we get is fog. Frost is also called freezing fog due to this.

A dew point is where the water vapor or moisture in the atmosphere cools to form a liquid. This phenomenon is called condensation, the opposite of evaporation. The liquid then turns to ice if the temperature gets cold enough. The ice crystals formed are known as frost.

The type of frost on your windscreen is termed “window frost .” This happens when the windshield is exposed to the cold air outside with even colder trapped moisture on the inside. Winter residents in cold climates are familiar with. During winter, there’s an increase in air moisture.

The cold air settles down on the earth’s surface as it is heavier or denser than the warm air. As the temperature continues to drop due to longwave emissions, the earth surfaces the moisture in the air condenses to form tiny air droplets.

However, moisture and water vapor trapped inside your car also concentrate on the cold surface of the windscreen. And without your car heater on, the insides get even colder than the outside atmosphere. As a result, an ice crystal termed frost is formed.

As your windshield heats up during the day, the absorbed sun rays are re-emitted to the atmosphere during cold evenings. This leaves the glass surface colder allowing moisture to settle or condense.

The higher the humidity during winter, the more ice is formed. Frost on Inside your windshield indicates that there’s too much moisture trapped in the car.

You might wonder how water vapor gets trapped in your car. Snow from your boots, jackets, and socks during winter can get into your vehicle. The snow melts, then evaporates during the day and condenses on your inside windshield as the night gets colder.

How to stop frost from forming on the inside of the windshield

Without a garage to protect your car, frost forms in just one night. Scraping the outside snow is the limit to your snow scraping. Frost inside your windscreen shouldn’t be scraped. There are more comfortable ways to fix this, but here’s what you should not do;

Do not use hot water

using hot water for defrosting could damage your windshield or, even worse- if you’re a bit clumsy and get soaked unintentionally. Your windshield is made of laminated glass. It expands in hot weather and contracts in cold weather.

The sudden change in temperature from hot to cold could cause your windshield to crack. The crack could later spread all over. Restrain from using hot water or blasting your frosty windscreen with hot air.

Do not leave the car windows open

Now, if you do not have a garage to protect your car from the cold, you shouldn’t leave the windows open even slightly, especially on breezy nights. More moisture could get in, and you have a car full of snow the next day.

However, leaving your car windows slightly open could release trapped moisture inside and reduce the amount of frost formed if you have a garage.

Nonetheless, to get rid of frost on the inside of your windshield, here’s what you can do:

  • Warm-up

Turn on the car heater and wait for about 15 minutes; the frost melts gradually. And you can scoop the melting liquid with a heated cloth to hasten the process. You can also get an affordable car defroster. And direct the hot air towards the windshield. It might be faster.

  • Keep ice off your clothing

Before entering the vehicle, brush off the ice stuck to your shoes, hat, or boots. Make sure you also dry the floor mats.

  • Air recirculation

Turn on the AC and turn off the air recirculation. When defrosting your car, you want to recirculate the damp air from the melting ice. Instead, you want to exchange the damp air with the warmer outside air. This way, the temperature inside the car balances with the atmospheric temperature outside. As a result, ice cannot condense on the car’s surface. Your windshield would defrost much faster as the inside air gets warmer.

  • A moisture absorber

You can procure a moisture absorber or drying agents, or dehumidifiers. A packet of silica gel is suitable. Moisture absorbers work best while using a defroster. The ice is melted to vapor and passed out through the air vents. The silica gel then absorbs more moisture, decreasing car humidity. A box of baking soda opened up inside the car reducing fog by absorbing the moisture.

Conversely, you should check out your door seals if you’ve done all these and still ended up with a frosty windscreen. Damaged door seals allow moisture sneaks into your car. They should be replaced as fast as possible.

Is frost on the inside of the windshield dangerous?

While the ice crystals pose no apparent threat, if present on windshields, it reduces vision and makes navigation in vehicles difficult. This makes it dangerous. You don’t want to drive with frosty windshields because you’d barely notice anything in front of you- from an opposition vehicle to the animals and pedestrians.

What is the fastest way to stop frost on the inside of my windshield?

If you’re in a hurry and need to rid your windshield of ice as quickly as possible, you can use vinegar mixed with water or rubbing alcohol mixed with water. So, you make one-part vinegar or rubbing alcohol with three parts water.

Ensure that the water isn’t too hot or too cold. Relatively warm water works great. Pour this mixture into a spray bottle and use it on your windshield. And then, with a heated-up cloth, you dry the windshield. You could also use a heated-up cloth straight away, whichever is more comfortable.

Another quick hack for defrosting your windshield in a short period is using a sandwich nylon or polythene bag filled with hot water. Then you hold the bag on one end and move it across your windshield. This should dissolve the ice faster. Afterward, you use a piece of cloth to take up the melted ice. A dry towel would work well in this case. A packet of silica gel to absorb the humid air is also suitable.

During winter, you take the pain to defrost your windscreens as drivers need complete visibility. Otherwise, we take the risk of accidents and even a lawsuit for reckless driving. Criminal penalties in the event of someone getting hit.

Also, while using a defroster, you must ensure that the evaporating humid air is exchanged with the warmer atmosphere outside the vehicle. Otherwise, the damp air settles back on your windshield and forms frosty crystals again.