A small stone chip can sit quietly on your windshield all summer, then turn into a crack across the glass on the first −30°C morning. Cold weather doesn't usually cause damage on its own, but it makes existing damage spread fast. Here's why, and what Portage la Prairie drivers can do about it.
Why cold weather spreads chips and cracks
Windshield glass expands when it warms and shrinks when it cools. On a winter morning, the outside of the glass might be −25°C while your defroster blasts hot air on the inside. That difference puts stress on the glass, and any chip or crack is the weakest point. The stress concentrates there, and the damage grows.
Moisture makes it worse. Water from melting snow seeps into a chip, freezes overnight, and expands. Each freeze-thaw cycle pushes the damage a little further. Add potholes, frozen ruts and gravel on Highway 1 and the Yellowhead, and winter is the season most chips become cracks.
Common winter habits that crack windshields
Pouring hot water on an iced windshield. The sudden temperature jump can crack even undamaged glass.
Blasting the defroster on high right away. Start it on low and let the glass warm gradually.
Scraping hard with a metal tool or the edge of a credit card. Use a plastic scraper and let the defroster loosen the ice first.
Slamming doors on a frozen vehicle. The pressure change and vibration can push a crack further.
Following trucks and sanders too closely. Winter road sand and gravel are a leading cause of chips.
7 ways to protect your windshield this winter
Fix chips before the cold sets in. A chip repair takes about 30 minutes and stops the damage from spreading.
Warm the car gradually. Use a remote starter or start the engine and let it idle a few minutes before turning the defroster to high.
Park in a garage or facing away from the wind when you can.
Use a windshield cover overnight to stop ice from forming.
Replace worn wiper blades. Old blades drag grit across the glass and can't clear slush.
Use winter washer fluid rated to at least −40°C so it doesn't freeze on contact.
Leave more space behind trucks and sanders, especially on the highway.
Chip repair is free for most Manitoba drivers
As of April 1, 2026, stone chip repair costs $0 at every MPI extension deductible level: Extension $200, $300, $500 and $750. Only drivers on the $1,000 basic deductible pay for chip repair. And glass claims don't affect your MPI rates, premiums or Driver Safety Rating.
Not sure what your deductible is? Check the "ALL PERILS" line on the white portion of your vehicle registration. See our MPI deductible guide for full costs.
When it's too late for a repair
If a chip has already spread into a long crack, or the damage sits right in the driver's line of sight, the windshield usually needs replacing. A replacement typically takes 2–3 hours, plus calibration time for vehicles with lane-assist or collision-warning cameras. Learn more about our windshield replacement in Portage la Prairie.
Get your chip fixed before it spreads
AA Auto Glass is an MPI accredited glass shop at 175 8 St NE in Portage la Prairie. We open your MPI claim for you, bill MPI directly, offer mobile service and free vehicle pickup and drop-off in Portage, and back every repair with a lifetime workmanship warranty.
Open your MPI glass claim online in about 2 minutes, or call 431-244-9606.
