Help for Fogging Windshields | Scott's Fort Collins Auto

Help for Fogging Windshields

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Fogging windshields happen to everyone. The reason for this regular annoyance has to do with temperature and the air’s moisture content. In the winter, moisture turns into condensation that fogs the windows. However, you can have fogging windshields even in the summer, it’s just not as common. When it does happen, what can you do about it? Here are some tips!


Fogging Windshields: Why Do They Happen?

On a cold day, any moisture in the air inside your car turns into condensation when it hits air next to the windows. That only happens if that air it’s hitting is below a certain temperature called the “dew point”. This is defined as the “atmospheric temperature below which water droplets begin to condense and dew can form.” That dew will be the frost that is causing fogging windshields.


This is different than humidity. Humidity is simply water/moisture in the air. The dew point is the point when all that moisture finally creates water droplets that are visible. This can look like fog, which is why it’s referred to as fogging windshields or fogging windows. However, if you touch it, it will feel wet to you.


Moisture can come from the snow on your boots, ice on your clothes if it’s snowing when you’ve been walking to your car, and even passengers in the car exhaling. All these things are different temperatures that are all clashing with the heat turned on in the car compared to the cold outside that is also hitting your windshield. The condensation that is there is what creates fogging windshields. If it happens to you fast in the winter, then there is a lot of moisture in the air reacting to all the different temperatures. On a hot, humid day, the opposite happens, when the muggy air outside your car reaches the dew point against your windshield after it’s cooled by your AC system.


What to Do in the Winter

Fogging windshields and frozen windshields go hand-in-hand. Both will impede visibility or make it impossible as a driver. For frozen windshields:

  • Keep an ice scraper with you and a separate one in your car. You will want only an ice scraper that is actually for a car. Don’t use spatulas, credit cards or other straight edges to scrape a car, as these can leave scratches. Use the brush side of a scraper to get piled snow. Then, firmly scrape all the windows of your car.
  • For faster windshield cleaning, start the car, crank up the heat and the defroster. This will warm up the car while also getting the fogging windshields under control before your drive. Hopefully, the car will be toasty after a few minutes and it will run smoother during your commute.
  • Keep extra windshield wiper fluid in your vehicle if you end up running out of it while you’re driving. In the winter, windshield wiper fluid gets used up faster than it does in the summer due to snow, dirt and especially salt on the road. Always make sure it’s filled to have clear visibility on the road, especially when there’s lots of traffic.
  • Reduce your chance of fogging windows by knocking snow from your boots and brushing it off of your clothes when you’re getting into a car.
  • Bring a microfiber or other soft towel to wipe off the windshield from the inside of the car if fogging windshields won’t clear up. Sometimes, there is too much moisture for fast clearing to happen.


What to Do in the Summer

No matter if you are traveling in the summer or winter, make sure you give yourself extra time to plan for unforeseen events. Five minutes should be a good buffer if you’re heading to work and don’t know what your car looks like after snowfall or a storm. If it’s very hot outside and your air conditioning makes it very cold inside your car, you may be facing fogging windshields yet again. This is happening because the difference in temperatures on either side of the windshields is so different.


Fogging windshields in the summer are much more common in places that are humid because there is available moisture in the air to actually condense. This may happen commonly when driving in rain as well because of that moisture. If you commute often, check the weather in the morning, as you will be told if the dew point is high for that day. If so, expect your windows to fog up. In the winter, the air conditioner will kick on to some degree when the defroster is turned on in order to dehumidify the air and clear windows faster. In the summer, you may have to crank that a/c right up on your dash so the windows clear quickly. Still keep a towel in your car if that fogging doesn’t subside quickly enough.


Keeping Clear Windshields Year Round

It’s incredibly important as a safe driver to make sure that your windshields are free of obstacles, snow, fog and anything that would block your field of vision. In some states or counties within a state, it may even be a misdemeanor crime if you don’t have our windshields clear enough to see out of. That’s how important it is to have clear views in every direction you look. Make sure you clear fogging windshields when they start to happen, especially when the fogging is small. Crank up your defroster for the front and back windshields and turn the heat on. Periodically turn on that heat for longer drives to clear away the fog.


If you wake up in a hurry and have snow on your car, take the extra 5 minutes to clear off all the windows. If you get cracks in your windshield, have trouble with your defroster and heating system, or if you want to know more tips to clear your fogging windshields, call Scott’s Fort Collins Auto today at (970) 682-4202!

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