Why Arizona Heat Cracks Windshields (And How to Stop It)
A 20-degree temperature swing in 30 minutes is normal in Phoenix. Your windshield does not love that.
Phoenix windshields fail in summer for one reason: thermal stress. A windshield sitting in 145°F sun, then hit with cold AC air, expands and contracts. If there's already a chip, that chip is now a crack.
What actually happens
Glass expands when hot and contracts when cool. The outer layer is hotter than the inner layer (your AC is fighting the sun). The two layers move differently. A chip is a stress concentrator — the crack grows along the path of least resistance.
How to prevent a chip from spreading
Park in shade. Use a sunshade. Don't blast cold AC at a windshield that's been baking — start the fan low and ramp up. And get the chip filled within a few days, not a few weeks.
When to stop driving
If the crack is in the driver's line of sight, longer than 6 inches, or crosses an edge — you're driving on a windshield that can fail in a collision. Get it replaced.
Free quote: (602) 904-9271. We come to you.