A cracked windshield can be annoying at best and completely unsafe at worst.

A crack in a windshield can be fairly small and easy to fix, or it can be large enough to require a complete windshield replacement.

Windshields To Crack

If a crack is large enough, it can be a potential safety hazard, because it can not only limit a driver’s view, but it can also possibly cause your windshield to completely shatter unexpectedly.

Because of this, it is important to have your windshield fixed immediately once you notice a crack in it, even if you think it is small enough to not cause any further problems.

On top of that, of course it is also important to work to avoid windshield cracks whenever possible.

Here are the top 5 causes of cracks in a windshield:

Rocks & Dirt

Rocks hitting the windshield are the most common cause of windshield cracks.

Many times rocks can get caught under the tire of a car driving in front of you, and can be shot up from the tire, hitting your windshield.

This can cause a small, or even a large crack in your windshield.

Large amounts of dirt can also cause weaknesses in your windshield, which can help to cause cracks from other sources.

The Sun

The sun is another common cause of cracks happening in a windshield.

This may sound surprising to you that the sun can actually cause cracks in the windshield.

But just think about how hot your car is when you get into it on a hot, sun filled day.

Now remember that your windshield is also being exposed to this same heat that you are being affected by.

So, with very high temperatures, heat from the sun can cause your windshield to crack, or even shatter in extreme cases.

Heat from the sun can also make existing cracks worse.

Temperature Changes

Let’s keep talking about those extremely hot days that we talked about in #2.

What is usually the first thing you do when you get into that very hot car?

If it’s blast the air conditioner, you may be causing potential harm to your windshield.

Just like extreme hot temperatures can cause cracks or shattering, extreme cold can also have the same effect on a windshield.

And too quick temperature changes from these extremes compounds these problems.

Causing your windshield to experience quick extreme changes in temperatures is like asking for a crack to develop or a shatter to occur.


If moisture gets in between the two layers of your windshield (usually through an existing crack), it can cause cracks to get worse, especially if it’s very cold outside, causing the water to freeze and expand.

So, if you have an existing crack in your windshield, try to keep it out of the rain or a car wash, and make sure to get the crack fixed as soon as possible, especially in the winter.


As you can see, many of the causes of cracked windshields are unavoidable.

While some of the causes of cracked windshields can be avoided (don’t follow other cars too closely to avoid rocks shooting up into your windshield, don’t immediately blast your AC on a hot day, etc),

most of them are common factors that many of us face each day (the sun, rain, etc). Also notice that many of these problems not only cause cracks, but they will make existing cracks get much worse.

That is why it is so important to get a crack, even a small one, fixed as soon as you notice it, because if a current crack is exposed to any of the elements listed above,

it can turn from a small, easy problem, to a much larger, much more complicated (and expensive) fix.

This article was contributed by Nicole. She writes for the  car care industry. She recommends Instant Windscreens as a great windshield replacement company.