How To: Defrost a Windshield


Use the defrosting methods described in this article to keep your windshield clear for winter driving.

If you have ever parked outdoors during sleet or on a cold winter night, you well remember the frustration of waking up to a windshield covered with frost or thin ice. The solution, to keep the engine running with the defroster on and wait for the problem to resolve itself, is an act that wastes precious time and gasoline. Alternatively, you may opt for a labor-intensive windshield scraping in the cold outdoors.

Fortunately, there are better and faster ways to solve the problem and get on the road safely. Below are three techniques for defrosting your windshield and preventing it from freezing.

How to defrost a windshield with slightly warm water

Fill a gallon-sized bucket three-quarters full of warm water. (If you pour hot water on a frozen windshield, the temperature difference will cause the glass to expand and possibly break.)

Pull the bucket over to the car and gradually pour the water over the frozen windshield. Starting from the upper left or right, pour water horizontally onto the glass.

As the warm water drips down, the ice in its path will quickly thaw and turn to opaque slush. Use windshield wipers or wipe the windshield with gloved hands to remove it.

Use the remaining warm water to thaw the frozen window.

How to defrost a windshield using alcohol wipes

Alcohol, which is used to clean small abrasions, is an effective de-icing agent because it has a much lower freezing point (-128 degrees Fahrenheit) than water. When applied to a frozen windshield, the alcohol itself does not freeze, but its heat is transferred to the ice, raising its temperature and melting the ice.

  • Add 4 oz. of room temperature water and 8 oz. of alcohol to a dry 12 oz. spray bottle, replace the nozzle, and turn the bottle upside down several times to mix.
  • Spray over your windshield to completely coat the glass, then let the solution dwell for one minute, allowing the alcohol to seep into and soften the ice.
  • Wipe off the icing with gloved hands or scrape off with a plastic credit card.

Once the windshield is clean, store the spray bottle in the glove box or trunk so that you can address the freezing problem when you leave home. The freezing point of rubbing alcohol is very low, so there is little danger of the de-icer freezing.

How to Defrost a Windshield with a Homemade Heat Pack

Want to remove ice from your windshield in the warmth and comfort of your car?

  1. Fill an old sock or two gloves with brown rice and heat them in the microwave for 30 seconds.
  2. While sitting in the car, hold the socks in both hands and gently slide them over the entire inside of the windshield. At this point, be careful not to leave the socks in one place for more than 10 seconds (the risk of breaking the glass increases).
  3. The heat from the rice will transfer to the glass and begin to melt the ice on the windshield.
  4. When the ice is sufficiently melted or softened, move the wipers to remove the ice.

How to prevent frost from forming on the windshield

Here are a few ways to keep ice and frost off your windshield before your next drive

  • During cold weather, close your windows as much as possible and park your car in a garage.
  • If you don’t have indoor parking, cover your car with a tarp or place a few beach towels or rubber mats on the windshield and use your windshield wipers as clips to hold the cover in place. This will act as a shield for frost and ice buildup and keep the glass below it clean and clear.
  • Place an old sock or knee-length sock over the wiper blades to keep dew and snow from reaching them.