How Summer Heat Can Make Auto Glass Cracks Worse in Bloomington & Terre Haute, IN And What You Can Do About It

📍 Serving Bloomington, Terre Haute & the Wabash Valley

Indiana summers bring intense sunlight, high humidity, and rising temperatures, conditions that can make small auto glass cracks spread faster than you might expect. Heat puts extra pressure on your windshield, and when combined with sudden cooling from your AC or shade, existing cracks can quickly worsen.

Here’s why hot weather affects your windshield, what to watch for, and how to prevent minor damage from turning into a full replacement.

Why Heat Makes Windshield Cracks Spread

Auto glass expands when heated and contracts when cooled. In summer, your windshield might reach high temperatures in direct sunlight, even if the outside air feels comfortable.

Heat can worsen cracks because:

• Expansion causes stress along crack lines

• Sudden cooling (like A/C blasting) can shock the glass

• Weakened areas spread under thermal pressure

• Existing chips become longer cracks

If you notice new damage or spreading cracks, schedule repair quickly.

The Danger of Parking in Direct Sunlight

Your windshield can reach extreme temperatures when exposed to direct sunlight, sometimes over 140°F on a hot day.

Direct sunlight can:

• Accelerate crack growth

• Cause the inner layer of the windshield to weaken

• Increase glare from imperfections

• Make the cabin heat up faster

If your crack reaches the edge of the windshield, replacement is typically required.

Avoid Sudden Temperature Changes

Rapid cooling is one of the biggest causes of crack expansion in summer.

Avoid the following:

• Blasting cold air on a hot windshield

• Turning the A/C to max immediately

• Pouring cold water on hot glass

• Parking half in the sun, half in the shade (uneven expansion)

Gradual temperature changes help protect the windshield structure and minimize crack spread.

Fix Chips Before They Become Long Cracks

A chip the size of a dime may seem harmless, but summer heat can turn it into a long crack, often too big to repair.

Chip repair is:

• Fast

• Affordable

• Usually covered by insurance

• The best way to prevent major repairs

Learn more about chip repair and small crack repair.

Replace the Windshield If Cracks Spread Too Far

If your crack is:

• Longer than a few inches

• Growing in multiple directions

• Reaching the edge of the glass

• Obstructing the driver’s line of sight

…it’s time for a full replacement. Driving with a large crack compromises visibility and structural safety.

Schedule replacement here.

If your vehicle has ADAS systems, recalibration may be required.