4 Reasons Why Your Windshield Fogs Up

Is your windshield fogging up just a few minutes once you start driving? This is a common problem that occurs due to various reasons. It’s important to understand why fogging up occurs on your windshield so that you can find the right solution.

Remember that a foggy windshield can be a cause of a serious accident. It’s important to know more about this problem before it happens to you on the road.

Why do windshields fog up?

The following are the reasons why windshields fog up while you drive:


When a moist outdoor area hits the cold windshield of your car, condensation occurs. The moisture will stick on the glass, which will cause fogging. This happens a lot during the morning, but it can also occur at any time of the day.

Condensation happens because the temperature inside your car is different than on the outside. This difference will turn vapor into the water as it hits the windshield.

Take note that condensation can impede your vision on the road. No matter how much you use your wiper, condensation can continue to build up.


High humidity levels mean that there’s an abnormal amount of moisture in the air. This airborne moisture will stick into your windshield and cause fogging.

This happens a lot when there are many people inside the car. As more people breathe out humid air, the risk of windshield fogging becomes high as well.

Surface tension

When moisture hits your windshield, it will bond with other water molecules. In a few minutes, this will create a chain of water molecules until there’s surface tension. To remove the fogging, you need to break the surface tension by disturbing the surface. You can use your wipers for this one while driving.


Hot air holds more moisture, which explains why your windshield will fog when it’s warm inside the car. Aside from that, molecules have more space between each other in warm conditions. This will allow water molecules to fit in.

How to fix a fogged-up windshield

Fogging is a common problem with very easy solutions. If you keep encountering this issue on the road, the following are the things you can do:

  • Stop air recirculation. If your windshield is fogging during cold conditions, you should avoid using the air recirculation button. This function allows cold air to enter your car, which will cause condensation on our windshield.
  • Neutralize the temperature. When the temperature inside the car gets hot, and the outside temperature is cold, moisture will form on your windshield. It will help to crack the window open to neutralize the temperature and remove the fogging.
  • Use your wipers. In warm conditions, you can fix a fogged windshield by activating the wipers. The wiper blades will disrupt surface tension and remove the accumulated moisture.


Remember that foggy windshields create a dangerous environment for you and other drivers. It’s important to know how to handle this whenever it occurs on the road.

You should maintain your windshield properly to remove other problems that could affect your vision. A local car detailer can also help solve fogging problems if it keeps happening.