Yes. And September can be a good time to see it happen. In September, two years ago, Springfield averaged a high of 82.7 degrees and a low of 59.8 degrees, a swing of roughly 23 degrees between afternoon and early morning, according to the National Weather Service. Temperature changes like these can add stress to an already damaged windshield, increasing the chance that a small chip will develop into a longer crack while your car sits in the driveway.
Why Temperature Is the Real Culprit
Glass expands when it warms and contracts when it cools. An undamaged windshield can accommodate those changes relatively well, but a chip creates a point where stress can become concentrated. As the glass heats and cools, that damaged area can experience additional stress. Over time, or during a significant enough temperature change, that stress can cause an existing crack to extend. Our post on protecting a new windshield covers this same stress response in more detail.
It Doesn’t Take Extreme Weather
People tend to picture this happening in the dead of winter or the peak of summer, but temperature changes can occur just as readily during the shoulder seasons. A warm afternoon followed by a cool night creates a different set of conditions than a stretch of relatively steady temperatures. A damaged windshield may tolerate those changes for a while, but repeated heating and cooling can contribute to crack growth.
What Actually Happens Inside the Chip
A chip isn’t necessarily just a clean hole in the glass. An impact can create small fractures that extend outward from the point of contact, even when some of them are difficult to see. Changes in temperature can place additional stress on those existing fractures, allowing them to grow. That’s one reason a chip can appear stable for days or weeks and then develop into a much longer crack. The damage was already present; changing conditions can help it progress.
What You Can Actually Do About It
Parking in a garage or shaded spot can reduce how much the windshield heats up during the day, which may reduce temperature-related stress but doesn’t eliminate the risk. Avoid directing very hot or cold air onto a damaged area of the windshield, particularly when the glass is already under significant temperature stress.
The best way to prevent a small chip from becoming a larger problem is to have it evaluated and, when appropriate, repaired before the damage spreads. Resin repairs can fill the damaged area and help stabilize the glass, although not every chip is repairable.
Don’t Wait Once You See It
A chip that is repairable today may become a crack that requires windshield replacement later. The difference can affect both the type and cost of the repair. Missouri’s vehicle inspection standards also place limits on certain types and locations of windshield damage, so a crack that spreads can create additional problems.
If you’ve got a chip you’ve been meaning to deal with, it’s worth having it evaluated before the damage spreads. Contact Kirk’s Collision Center and we’ll take a look.