Can A Car Window Shatter From Heat?

With the hottest part of summer just around the corner, there are many questions that are often asked by those concerned with the heatwave. Is it safe to go outside? Did we really have to cancel that pool membership? I wonder if I can cook eggs on the sidewalk as I saw in that one video. All jokes about the heat aside, many auto owners find themselves worried about the integrity of the glass in their cars. Will the rising heat cause the glass to shatter? The simple answer is that, barring previous damage to the integrity of the vehicle or the glass, no, the glass in your car will not shatter due to the heat.

While many people believe that the thermal expansion of the glass caused by the hot sun can cause it to crack and then shatter, it is nearly impossible for it to occur in reality. Even if the glass was set in a perfect frame, snugly held in place without a single loose area, the glass cannot expand enough to cause any sort of damage. As it is, the glass in cars is set fairly loosely, with the exception of the front and rear windows which are set in rubber frames and slightly curved, allowing the glass to handle even extreme thermal expansion at a level that could never be caused by changes in the weather.

How Does Heat Affect My Car Window

Another myth that people claim could cause the shattering of car windows is the expansion of air within the car caused by the heat, wherein it expands so much that the glass can no longer handle the internal pressure and fractures. This is impossible, as cars available commercially are far from airtight, meaning that such a tremendous amount of pressure could never build up without first escaping from the car. Even if your car had perfect air integrity, the change in pressure from natural weather changes is minimal at best, having little to no effect.

In short, there is no need to worry about the glass in your car shattering or exploding due to the heat, so long as you have no previous damage to the structure of the car or the windows beforehand. The tempered glass used for car windows is incredibly durable, which is why it was designed for cars in the first place.