One of the worst things about driving in the winter is waiting for your windows to defrost before getting on the road -- especially when you're already running late. 

There are many urban legends surrounding the easiest ways in which to defrost your windshield. From using shaving cream to kitty litter, some have been given more credence than others.

Fluctuating temps are no joke when it comes to your glass, and while everyone (hopefully) knows you never add hot water to a frosted windshield, it’s sometimes hard to find the best solution. But there is one surefire way to determine the best, most efficient ways to defrost your windshield: science.

As it turns out, there is an easier way to defrost your windshield than just blasting the defroster, and the pros at Only 1 Auto Glass are here with the answers!

What Science Tells Us

First, it's important to understand why your windows fog up in the first place. All air around us has at least some amount of moisture in it that we can't see.

This is called water vapor. The higher the humidity level, the more invisible water vapor is in the air. Once the humidity level passes 100 percent, it forms condensation. This is, essentially, what causes your windows to fog up.

But what most people don't know is that hot air can hold more moisture than cold air. Meaning warm air is like having a bigger towel to dry off, while cold air is like trying to dry your body with a washcloth. The same logic applies to clouds, fog, and even your breath on a really cold day. 


Since warm air can hold more water vapor, it can remove condensation faster. Mark Rober, an enthusiastic YouTube sensation, says he used science to discover the best way to defrost a window. This video explains it best.

Here's what he found:

  • Turn the heater on at full blast
  • Turn AC on
  • Turn off the inside air circulation
  • Crack open the windows

Rober's experiment found that this method cleared the windshield twice as fast as any other combination of A/C settings. And while this can be ideal for some circumstances, if you don't have time to wait for your car's heater to warm up, we have a few other proven methods we stand by

Apply De-Icer Spray to the Glass

If you’ve never used de-icer spray to get stubborn ice off your windshield, it’s time you give it a try. Compared to an ice scraper, a de-icer is safer for your auto glass because it minimizes the risk of unintentional damage and the need for subsequent windshield repairs. De-icer spray also eliminates ice faster than an ice scraper and is remarkably easy to use.

If you want to give de-icer a try, choose from one of the following options:

Alcohol-Based Spray

You can make a homemade de-icer on the cheap by combining one part water and two parts 70% isopropyl alcohol. Pour this solution into a spray bottle and apply a light layer to the ice on your windshield.

Saltwater De-Icer

Using a saltwater solution is another highly effective way to de-ice your windshield. Just pour room-temperature water into a spray bottle, add a few spoonfuls of salt, let the salt dissolve, and spray the solution on your icy windshield. For best results, use road salt rather than table salt.

Store-Bought De-Icer

Commercial de-icers are widely available at auto supply shops and big box stores. These also work well, but they’re considerably more expensive than their homemade counterparts, so if you’re de-icing almost daily, opting for the DIY route is far more economical.

Avoid Chipping or Pounding on the Ice

Even when you use a plastic ice scraper to de-ice your windshield, you need to use it properly. Whatever you do — even if the ice is super thick and stuck on — don’t pound or chip at it! Your windshield is vulnerable to damage in extreme temperatures.

If You’re De-Icing With a Tool, Make Sure It’s Plastic

If you have a dedicated ice scraper in your vehicle, great! That’s what you should always use for de-icing to avoid scratching your auto glass and needing windshield repairs. But if you don’t have an ice scraper to get the job done, whatever you do, don’t use metal tools!

Using tools that are super rigid or hard to de-ice your auto glass is a disaster waiting to happen. You can easily scratch or chip the glass with just a hair, too much pressure, or a slip of the wrist. Without prompt windshield repair, that damage will likely grow since chips and cracks are susceptible to spreading as temperatures fluctuate throughout the day.  

Use Tepid Water

If you’re in a major hurry and need to de-ice your windshield quickly but can’t find your scraper, try using tepid (never hot!) water to get the job done. To de-ice auto glass with tepid water, you only need to pour the water slowly and steadily onto the glass.

Do not use hot water! Much like an ice cube cracks when it’s exposed to a sudden, dramatic temperature change, your auto glass can do the same thing when exposed to hot water. 

It’s also a good idea to have your defrost on while you do this. But make sure you always start your defrost on low and gradually increase it to high to avoid exposing your windshield to a drastic temperature shift that results in needing a replacement or repair. 

Combine Defrost, De-Icer, and Scraper for Rapid Results 

If you’re in a huge hurry and need to get ice off your windshield quickly, combining all the tools in your toolbox is the best way to get the job done. Here’s what you need to do:

  • Apply one of the three de-icer sprays above to your windshield and allow it to sit for a few minutes.

  • Start your vehicle and turn on the defroster.

  • After the de-icer has had a few minutes to work and your defroster has also started to melt the ice, use a plastic ice scraper to gently chip away at the chunks of ice on the glass.

  • As you loosen pieces of ice, sweep them onto the ground and use your windshield wipers to remove any remaining de-icer or water.

Tip: If there are any chips in your windshield, it’s in your best interest to avoid using an ice scraper until you handle the necessary repairs. Any amount of pressure on the glass can cause the existing damage to spread.

Prompt Windshield Repair or Replacement at Only 1 Auto Glass

Whether you need windshield chip repairs, crack repairs, or a complete windshield replacement, let our team at Only 1 Auto Glass help you out! We offer both in-shop and mobile auto glass repair and have multiple locations throughout the Minneapolis/St. Paul metro area for your convenience. 

To get started or learn more about how we can help you, feel free to give us a call today at 651-789-1111 or request a free estimate online, and we’ll get back to you right away!