How to Get Ice Off a Windshield with Water

Since nights are colder than days, it’s common for ice to form on your windshield into ice at night during the cold months of winter. Scraping the ice off can be a pain and waiting for your car to warm up and defrost the windows is both time consuming and a waste of petrol.

However, there are multiple ways you can get ice off a windshield with water whilst also keeping your windshield safe from cracking.

You should NEVER pour hot or boiling water onto an icy windshield as it can cause the windshield to crackThe best way to get ice off a windshield with water is to mix one part water with one part isopropyl alcohol and spray the mixture on your frozen windshield. This will cause the ice to melt and it can be easily cleaned off with a scraper or the windscreen wipers.

If you don't have isopropyl alcohol then placing warm water in a bag or hot water bottle and running it lightly over your windscreen will melt the ice.

Battling with a frozen windshield can be time-consuming when you rely on manual scraping tools. Take the time to understand how a mix like isopropyl alcohol and water works to thaw ice, and you’ll begin to understand how to combat your problems with ice. 

Continue reading to learn how to best use a water and alcohol mixture and to learn other methods to melt ice or prevent it from forming on your windshield entirely. 

Avoid Hot Water

It may seem like a good idea to pour hot water over a frozen windshield to melt the ice. Avoid this at all costs because rapid temperature changes are likely to crack glass. 

Glass conducts heat poorly, which means the hot water will change the surface temperature while the lower layers remain cold. This temperature difference leads to stress fractures that turn into major cracks. 

So while this is a tempting way to try and melt ice off your windscreen with water it's not the way to do it!

Avoid Plain Cold Water

Pouring cold water over your frozen windshield won’t damage it as hot water can, but it won’t help your situation either. 

Cold water may begin to thaw any present ice on your windshield, but if outside temperatures are cold enough, the cool water will begin to freeze immediately. This can be made worse by driving as the cold air blowing quickly over the windscreen can freeze any water left on there.

By adding cool water to your windshield, you can increase the amount of ice present and make your cleaning task more challenging. 

It’s important to put an additive in your cool water before adding it to your windshield. Including a substance that prevents freezing will work wonders for clearing away the ice.

How To Quickly Clear Your Icy Windscreen With a Bag of Warm Water

While pouring hot water onto your car window can break it there is a really cool hack where you can remove ice from your windshield with a bag of warm water.

In order to use this technique you want to pour hot water from your tap or kettle (hot, not boiling) into a plastic bag. You can use a sandwich bag or a ziplock bag for this, just any bag that won't leak.

You don't need lots of water. Fill the bag up as if you're going to carry home a goldfish from the store.

Take the bag out to your car and place it on your windshield lightly moving it up and down to melt the ice.

This technique works best in milder weather and when there is just a thin layer of ice on your windshield. For thicker layers of ice and in colder weather this technique may not work.

Also, while you're using this technique you'll still want to have your car running and warming up the windshield. This means once you begin driving any remaining water won't re-freeze in your windshield ruining your visibility.

How To Clear Your Icy Windscreen With Water and Isopropyl Alcohol

Another great way to clear an icy windshield with water is actually to mix water with some isopropyl alcohol solution.

Isopropyl alcohol has a lower freezing point than water. It takes temperates as low as -128ºF/-89ºC to completely freeze isopropyl alochol.

When it mixes with the ice on your windshield it will lower its melting point too, causing it to melt, even in temperatures below 32ºF/0ºC.

Step 1 – Create the Mixture

Plain water isn’t effective for treating ice on your windshield because it’s likely to freeze and increase the problem.

To solve this issue, make a mixture that’s two-parts isopropyl alcohol and one part water. Ideally you want to use 70% or 99% isopropyl alcohol for effective results, but other types can work well too. 

Blend the mixture thoroughly to fully combine the alcohol and the water. 

Step 2 – Bottle It

Combine the alcohol and water in a spray bottle to make treating your windshield quick and easy.

The mixture can also be put inside a small pesticide sprayer for use throughout the winter months.

The good thing about this solution is it won't freeze even overnight. So you can leave it in your car and that way you'll be able to use it whenever you need to.

Step 3 – Spray and Wipe Away

Each time your vehicle’s windshield becomes coated with ice, take out your sprayer and liberally coat your windshield with your water and alcohol solution.

You’ll notice the ice begins to melt and break up immediately.

After a few moments, you can turn your windshield wipers on to help wipe away the accumulation completely.

This Works Best For Thin Layers Of Ice

This isopropyl alcohol spray works best for thin layers of ice. It'll cause the thin layer to melt quickly and then you can wipe it away with the windscreen wiper.

For thicker layers of ice the isopropyl will take longer to work. Scraping may still be needed on thicker layers of ice but the isopropyl alcohol mixture will make the scraping easier and will also make ice less likely to freeze on your windshield while you wait for the car to warm up.

You Can Use Salt Water For Faster Results – But It's Not Advised

While the water and rubbing alcohol mixture is effective at removing ice, saltwater mixture works as well.

Salt lowers the freezing point of water considerably, just as isopropyl alcohol does.

By lowering the water’s freezing point, you can use a cool mixture to thaw ice and effectively clear your windshield. 

Saltwater is thought to remove ice more effectively than a water and alcohol mixture, but it’s more corrosive to the metal components on your vehicle.

For your vehicle’s finish, it’s better to rely on de-icing methods that avoid salt when possible. 

Vinegar is another way to clear ice from your windshield. It only works in temperatures above 28ºF (-2ºC) so it's not the best option and it too is a big corrosive because it's so acidic. Not as bad as salt, and generally fine in small amounts, but still not ideal.

Cover Your Windshield To Avoid Ice

Instead of treating ice accumulation after letting your vehicle sit, you can avoid the issue by preventing ice on your windshield in the first place. One of the best ways to do this is by covering your windshield before ice forms.

You can use a towel on your windshield to prevent ice or you can use a waterproof blanket, such as this Yeti Lowlands Blanket – reviewed here, or use a windshield cover, garbage bags, or even cardboard for protection. 

Covers can be secured in position with the windshield wipers and by shutting them in the doors of the vehicle. 

Remove your cover when you’re ready to use your vehicle, and any ice accumulation will come off with the cover as long as moisture doesn’t permeate the cover fully. This is why water-resistant covers are more effective forms of protection against ice. 

Will Boiling Water Crack Glass?

When you’re trying to remove ice from your windscreen using water, it seems natural to consider boiling water as a solution. Is boiling water a good idea, or could it cause damage to your glass? 

Boiling water cracks glass when it causes it to change its temperature too rapidly. This is nearly always the result when boiling water is applied to frozen glass, such as a windshield in winter. Glass doesn’t conduct heat well, so the hot water causes some of the glass to heat up more than the rest, and the temperature imbalance leads to stress cracks. 

Getting an understanding of why extreme temperatures in glass is a problem can help you avoid damaging your windshield, frozen glass containers, and other glass items in your life that you’re tempted to heat in some way. 

Summary

You can remove ice from your windshield with water in 2 main ways. The most effective way is to mix water with isopropyl alcohol and spray it on your windshield to melt the ice away.

Keep your mixture ready throughout the winter months, and you can skip scraping ice for good. 

Another effective method is to fill up a plastic bag or hot water bottle with hot water (not boiling) and to gently rub this over your windscreen melting the surface ice.

Consider these other ice-removal techniques detailed here to help you keep your windscreen clear all winter and learn about how to maintain traction on walking paths using the techniques described here.