Summer Weather and Windshield Damage: What Colorado Drivers Should Know

Most drivers think of winter as the toughest season for windshield damage.

After all, Colorado winters bring freezing temperatures, snow, ice, and rapid temperature swings that can cause windshield cracks to spread.

But summer can be surprisingly hard on damaged windshields too.

If you have a windshield chip or crack, Colorado's intense sunshine, hot vehicle interiors, mountain driving, and sudden temperature changes can all place additional stress on already damaged glass.

Understanding how summer conditions affect windshield damage can help you avoid turning a small repair into a much larger problem.

Colorado Windshields Get Hotter Than Most Drivers Realize

When a vehicle sits in direct summer sunlight, the windshield can become significantly hotter than the outside air temperature.

Even when the air temperature is only in the 80s, the glass itself can become much hotter after sitting in direct sunlight for several hours.

The dashboard, steering wheel, and interior surfaces can also reach extremely high temperatures.

Most drivers have experienced opening a parked vehicle and feeling the intense heat trapped inside. That same heat is affecting the windshield.

For an undamaged windshield, this usually isn't a problem.

For a windshield that already contains a chip or crack, however, additional stress can sometimes contribute to crack growth.

Are Windshield Sunshades Always Helpful?

Most drivers assume that a reflective windshield sunshade keeps the windshield itself cooler.

Surprisingly, the opposite is often true.

A reflective windshield sunshade does an excellent job of keeping the vehicle's interior cooler by blocking sunlight from reaching the dashboard, seats, and steering wheel. However, that same sunshade can actually increase the temperature of the windshield glass itself.

Here's why.

When sunlight passes through the windshield, a reflective sunshade placed behind the glass bounces much of that energy back toward the windshield. The glass absorbs some of that energy a second time on the return trip.

At the same time, heat can become trapped in the small air space between the windshield and the sunshade. Instead of being absorbed by the dashboard and interior surfaces, more of that thermal energy remains concentrated near the glass.

For an undamaged windshield, this usually isn't a problem. Automotive windshields are designed to tolerate very high temperatures.

However, if the windshield already contains a chip or crack, the additional heat can increase thermal stress around the damaged area. In some situations, this may increase the likelihood that existing damage will spread.

A Better Choice for Damaged Windshields

If your windshield already has a chip or crack, an exterior windshield cover or reflective exterior sunshade may be a better option.

Because the shade is placed outside the vehicle, much of the sun's energy is blocked before it ever reaches the glass. This helps keep the windshield itself cooler and may reduce thermal stress on existing damage.

While no sunshade can guarantee a chip or crack won't spread, reducing unnecessary heat exposure is generally preferable when windshield damage is already present.

Why Existing Damage Can Spread During Hot Weather

Glass expands when heated and contracts when cooled.

Windshields experience these expansion and contraction cycles every day.

When a windshield already contains damage, those stress changes can sometimes cause a crack to continue spreading.

This does not mean every chip or crack will worsen during the summer.

However, many drivers are surprised when a crack that seemed stable for weeks suddenly grows after a period of hot weather.

In our experience, cracks often spread when multiple stress factors occur together rather than from a single event.

You can learn more in our guide to why windshield chips and cracks spread.

Small Chips Can Become Large Cracks

One of the most common situations we see is a small rock chip that is left untreated because it doesn't seem urgent.

Weeks later, the vehicle owner discovers a crack extending from the original damage.

Sometimes the crack appears after:

• A particularly hot day
• A road trip
• Hitting a pothole
• Driving on rough roads
• Sudden temperature changes

Once a crack begins spreading, repair options may become more limited.

This is one reason why earlier inspection is generally preferable whenever possible.

If a chip has already turned into a crack, see our guide on whether a cracked windshield can be repaired.

Be Careful With Sudden Temperature Changes

One of the biggest summer concerns isn't simply heat.

It's rapid temperature change.

Examples include:

• Spraying cold water on a very hot windshield
• Automatic car washes on extremely hot days
• Blasting cold air conditioning directly onto heated glass
• Sudden thunderstorms after prolonged heat

Most windshields tolerate these changes without issue.

However, damaged windshields already contain stress concentrations where cracks and chips exist. Sudden temperature changes may increase stress around those damaged areas.

This is especially true for existing cracks.

Summer Road Trips Create Additional Stress

Summer often means:

• Vacations
• Mountain driving
• Camping trips
• Road construction
• Longer highway drives

Colorado drivers frequently travel I-25, Highway 24, Highway 83, mountain passes, and rough construction zones.

Road vibration alone does not automatically cause windshield damage to spread.

However, vibration combined with existing damage, temperature changes, and normal vehicle flex can sometimes contribute to crack growth.

Many long cracks begin as relatively small damage that was exposed to repeated stress over time.

Bob's Windshield Repair can repair many long windshield cracks up to 14 inches, depending on the specific condition of the damage.

Avoid DIY Repair Kits

Summer is also a popular time for drivers to attempt DIY windshield repairs.

While repair kits are widely available, they often produce disappointing results.

Many do-it-yourself repairs fail because:

• Contamination has already entered the damage
• Insufficient vacuum is created
• Resin does not fully penetrate the break
• Curing is incomplete
• Expectations are unrealistic

In some cases, failed DIY repairs can make professional repair more difficult or even impossible.

If you're considering repair, professional evaluation is usually the safest first step.

We’ll cover this in more depth in a future guide on why DIY windshield repair kits often fail.

Summer Is a Good Time to Protect Your Windshield

A few simple precautions can help reduce stress on damaged glass.

If possible:

• Park in shaded areas
• Use an exterior windshield cover if the glass is already damaged
• Avoid sudden temperature shocks
• Address chips early
• Inspect cracks before long road trips
• Avoid DIY repair attempts

These steps won't guarantee a crack won't spread, but they may help reduce unnecessary stress on the windshield.

Don't Wait for a Small Problem to Become a Large One

Most windshield chips and cracks don't become serious overnight.

Instead, damage often worsens gradually as the windshield experiences normal daily stress.

Heat, vibration, road conditions, and temperature changes can all contribute to crack growth over time.

That doesn't mean every chip needs immediate emergency repair.

It does mean that a professional inspection is often worthwhile before the damage becomes larger, more contaminated, or more difficult to repair.

If you're unsure whether the windshield needs repair or replacement, our guide to when a windshield actually needs to be replaced may help.

The Bottom Line

Colorado summers can be surprisingly tough on damaged windshields.

Intense sunshine, hot vehicle interiors, road vibration, and rapid temperature changes can all place additional stress on existing chips and cracks.

Many small chips remain repairable for quite some time. Others may develop into larger cracks when exposed to enough stress.

If you've recently noticed windshield damage, summer is a good reminder that earlier evaluation is usually better than waiting to see what happens.

A quick inspection today may help preserve your original windshield and avoid more extensive damage later.