Why Do Car Windshields Fog Up?

foggy windshield

Depending on the temperature inside your car, your car’s windows, including the windshield, may fog up irrespective of the weather conditions.

For instance, in cold weather, you are likely to turn on your car’s heater to keep the temperature inside your vehicle comfortable. However, this may cause fog to occur inside your car’s windows. Similarly, in warm weather, you are likely to crank up your car’s air conditioning (AC) system in order to lower the temperature inside your car to comfortable levels. In turn, this may cause your car’s windows to fog up from the outside. With that in mind, here is some more information on this topic.

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Northampton County Auto Glass Repair: Why Car Windshields Fog Up

The two main factors that cause car windshields to fog up are temperature and moisture.

More specifically, in cold weather, any humid air inside your car will turn to condensation. This claim is especially true when it hits the extremely cold air next to your car’s windows that is below 60 degrees Fahrenheit (dew-point temperature). When this happens, your car’s windows will appear foggy.

Some of the things that increase the humidity levels inside your car include, among others, human breath, sweat, damp carpets, steamy beverages, and wet clothes. When you crank up your car’s AC system on a hot day, the opposite happens. Specifically, the hot muggy air outside your car hits the extremely cold air next to car’s windows, causing condensation to form outside your windows.

Of course, for safety reasons, you should defog your car’s windows when they fog up. Here are some tips on how to do that.

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Windshields & The Winter Season

car windshieldWhen you turn on your car’s heater in cold weather, fog may start to form on the inside of your car’s windows. To defog your windows quickly in cold weather, follow these steps:

  • Firstly, given that hot air can hold more moisture than cold air, crank up your car’s heater to its maximum setting.
  • Secondly, to dry the air inside your car, turn on your car’s air conditioning system.
  • Finally, turn off the recirculation feature and crack your windows for a few minutes to allow colder and drier air to get into your car.

It is important to note that, if you want to defog your car’s windows in cold weather, you allow the drier outside air to flow in your vehicle while at the same time enabling the relatively moist air inside your car to flow out of your car. Additionally, while driving, blow warm air across your windshield to remove the accumulating moisture.

Windshields & The Summer Season

In warm weather when the air surrounding your car is hotter than the air inside your vehicle, fog will form on the exterior of your windows. To defog your windows in such a situation, follow these steps:

  • Firstly, use your windshield wipers to eliminate the condensation.
  • Secondly, to ensure your car’s interior temperature does not drop further, turn off the car’s air conditioning system as well as its recirculation system.

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Car windows do not necessarily fog up because of cold weather. Instead, car windshields fog up when there is a significant temperature difference between the interior of a car and the air surrounding the car, the car’s windows will likely fog up.
More specifically, when the interior temperature of a car is hotter than the air surrounding the vehicle, fog may occur on the inside of the car’s windows. On the other hand, when the interior temperature of a car is colder than the temperature of the air surrounding the vehicle, the car’s windows may fog up on the outside. To improve visibility and avoid potential accidents, use the steps outlined in this article to defog your car’s windows.

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It is important to keep your visibility as clear as possible to ensure driving safely. Not only should you tank the steps outlined above to remove fog as a visual impairment, but you should also make sure that your auto glass is free from damage. If you have any windshield cracks or chips, be sure to have them repaired immediately.

When searching for the right auto glass shop, make sure to contact Liberty AutoGlass. We offer top-quality services, including windshield repairs, replacements, and more.

Rest assured that our experienced and certified technicians can address all your auto glass problems. We prioritize your needs by providing superior services at affordable costs. Call Liberty AutoGlass today for a free estimate.

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Contact us today or give us a call at (610) 377-7787 or (877) 90-GLASS if you have any questions. Click here to view our complete mobile auto glass service area in Pennsylvania.

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