Why Summer Heat Causes Tire Blowouts on London, Ontario Highways (and How to Stay Safe)

Every July, London's roads heat up right along with the tires rolling over them, and the pavement on the 401 and 402 can climb well past the air temperature on a sunny afternoon. Most drivers know winter is hard on a vehicle, but summer heat quietly wrecks just as many tires — it just does it faster and with less warning. If you've ever seen shredded rubber scattered along the shoulder near Westmount or Hyde Park, that's usually a summer blowout, not a winter one.

We get calls year-round for breakdowns across London — Byron, Masonville, White Oaks, Lambeth, you name it — but blowouts spike hard between June and August. Here's what's actually happening to your tires in the heat, and what to do if one lets go while you're driving.

Why do tires blow out more often in summer heat?

Heat is the enemy of rubber. As the temperature climbs, the air inside your tires expands, and the friction between tire and pavement generates even more heat on top of that. If a tire is already underinflated, its sidewalls flex more with every rotation, which builds up heat faster than a properly inflated tire can dissipate it. Do that at highway speed for twenty minutes on the 401 between London and Woodstock, and a weak spot in the rubber can fail without much warning. Add in a tire that's a few years old with worn tread, and you've got a recipe for a blowout on a hot afternoon.

What should I do if a tire blows out while driving?

The instinct is to slam the brakes — don't. A blowout pulls the car hard toward the side of the failed tire, and sudden braking makes that worse. Instead:

• Grip the wheel firmly and let off the gas gradually
• Let the car slow down on its own before easing toward the shoulder
• Avoid braking hard until your speed has dropped significantly
• Signal and merge onto the shoulder once you have control
• Turn on your hazards immediately

This matters most on stretches like the 401 through London or the 402 toward Sarnia, where shoulders are narrow and traffic doesn't slow down just because you're in trouble.

How can I prevent a tire blowout before it happens?

Most summer blowouts are preventable with a five-minute check before a long drive:

• Check tire pressure when tires are cold, ideally before you've driven that day — heat from driving will already have raised the reading
• Look at tread depth and watch for uneven wear, which signals alignment or suspension issues
• Inspect sidewalls for bulges, cracks, or cuts — these are often the actual failure point, not the tread
• Don't overload the vehicle, especially for road trips through Lambeth or out toward the cottage — extra weight means more heat per rotation
• Replace tires that are more than six years old regardless of tread depth, since rubber degrades with age even if it looks fine

What tire pressure is safe for summer driving?

Always go with the pressure listed on the sticker inside your driver's door jamb, not the number printed on the tire sidewall — that's the tire's maximum rating, not the recommended pressure for your vehicle. Summer heat naturally raises pressure as you drive, so check when the tires are cold and resist the urge to let air out mid-trip just because the gauge reads a bit higher after an hour on the highway. That's normal heat expansion, not a sign of overinflation.

Are older tires more likely to blow out in hot weather?

Yes, and this catches a lot of people off guard. Tires don't fail on a schedule based on mileage alone — the rubber compound breaks down with age and heat exposure whether the car sits in a driveway or racks up highway kilometres. A tire that looks fine with plenty of tread can still be five or six years past its safe service life. If you're not sure how old your tires are, check the DOT code on the sidewall — the last four digits tell you the week and year of manufacture.

Is it safe to drive on a spare to a repair shop?

Depends on the spare. A full-size matching spare is generally fine for normal driving, but most modern vehicles come with a compact "donut" spare rated for lower speeds and shorter distances — usually no more than 80 km/h and 100 km before you need a proper repair or replacement. If your blowout happens out near St. Thomas or Woodstock and you're relying on a donut, don't push it back into London on the 401 at highway speed. Get it to the nearest safe spot and call for a tow instead of risking a second failure.

When should you call a tow truck instead of trying to fix it yourself?

If you don't have a spare, if the rim is damaged from driving on a flat tire even briefly, or if the blowout happened somewhere without a safe shoulder to work on — a construction zone, a bridge, a tight curve near Masonville — don't attempt a roadside tire change. Traffic doesn't account for someone crouched at the side of the highway, and that's when a blown tire turns into something much worse. Get yourself and any passengers away from the vehicle and onto the far side of the guardrail if there is one, then call for help.

We're set up for exactly this kind of call

EMS Towing runs 24/7 across London and the surrounding area, and summer blowouts on the 401 and 402 are some of our most common calls between June and August. We carry the equipment to handle everything from a straightforward tire change to a full flatbed recovery if the rim or suspension took damage in the blowout. If you're stuck near Byron, White Oaks, Hyde Park, or out toward St. Thomas or Woodstock, we can get to you fast.

While you wait, our battery boost and lockout crews are also on call if the blowout wasn't your only problem today — sometimes it isn't. For anything on the highway shoulder specifically, our highway recovery team is built for exactly that kind of pickup.

Got more questions about what we cover? Check our FAQ page, or just call us directly at (226) 476-4176. We'd rather you call before a blowout turns into a bigger problem than after.