Most of us think about sun cream, sunglasses and topping up the screen wash when the weather turns warm and tyre pressure rarely makes the list. But tyre pressure in hot weather is one of those things that quietly causes problems all summer long, and by the time you notice, it’s usually because something’s already gone wrong on the motorway.

Here is what is actually going on when the temperature rises, and how to maintain the correct tyre pressure in hot weather.

Why Does Tyre Pressure Change in Hot Weather?

Tyre pressure isn’t a fixed number that stays the same all year round. It moves with temperature, because the air sealed inside your tyres expands as it heats up. On a warm day the road surface itself can be far hotter than the air temperature, and if you’ve been driving for a while, friction adds even more heat on top of that.

As a rough guide, pressure tends to climb by about 1 PSI for every 10°C rise. It doesn’t sound like a lot on paper, but if your tyres were already running a touch high before summer even started, that small increase can be enough to push them outside a safe range.

It works both ways, too. Plenty of drivers set their pressures back in the colder months and haven’t thought about them since. The reading might still look fine now, but if there’s wear or damage you haven’t spotted, running that tyre at motorway speed on a hot day is a different story altogether.

What Happens When the Pressure Is Wrong

Too much air in the tyre and you lose contact with the road, grip suffers, the ride gets harsher, and you’ll often see wear creeping down the centre of the tread rather than evenly across it.

Too little air, and the tyre flexes more than it should with every rotation. That extra flex builds heat inside the tyre itself, on top of the heat already coming from the road. Combine that with a long motorway stretch in summer traffic and you’ve got exactly the conditions that lead to a blowout which is why they’re so much more common in July and August than in the middle of winter.

Either way, it’s not something that shows up instantly. It builds the longer you drive, which is part of why a fifteen-minute trip to the supermarket rarely causes issues, but a five-hour drive down to the coast can catch people out.

So, What is the Right Tyre Pressure for Summer?

Here’s the thing, the correct pressure for your car doesn’t actually change between seasons. It’s whatever the manufacturer recommends, and you’ll usually find that figure on a sticker inside the driver’s door frame, tucked in the handbook, or occasionally inside the fuel filler flap.

What does change is how your actual pressure holds up once summer heat gets involved. To get an accurate reading and combat the effects of tyre pressure in hot weather, follow these steps:

• Check them when they are cold: Ideally, test your pressure first thing in the morning before the car has been driven anywhere or sat in direct sunlight.
• Avoid checking after a drive: Checking your tyres straight after a motorway run will give you an artificially high reading due to friction heat, which won’t give you a true picture of where things stand.
• Double-check before road trips: If you have a long summer holiday planned, check the pressures a day or two beforehand, then give them one final look on the morning you set off.

A Few Things Worth Doing Before a Long Drive

While monitoring your tyre pressure in hot weather is vital, it isn’t the only thing worth a quick look before a summer road trip:

• Tread Depth: A tyre can be sitting at the perfect PSI and still be dangerously worn. Ensure your tread is well above the legal limit.
• Sidewall Damage: Glance over the sidewalls for any cracking or bulging. High summer heat tends to worsen pre-existing rubber degradation.
• The Spare Tyre: If you have a spare wheel in the boot, summer road trip season is the perfect excuse to check if it’s actually inflated and usable.
• Slow Punctures: Heat has a habit of exposing slow punctures that you might never notice in cooler weather. Keep a closer eye on your pressure readings throughout the summer months.

When It’s Worth Getting a Professional to Look

If you’re not sure what pressure your car actually needs, if one tyre keeps losing air between checks, or you’ve got a long trip planned and just want peace of mind, it’s worth having someone properly inspect the tyres rather than just topping up the air and hoping for the best. A pressure gauge won’t tell you about wear, damage or ageing rubber but a proper check with expert will.

At FRM Automotive in Peterborough, tread depth, condition and pressure all get checked as part of every tyre service, so you’re not just leaving with more air in the tyres, you’re leaving knowing they’re actually fit for whatever drive you’ve got planned. So it’s worth booking in before your next long journey. You can call our team to find out more on 01733 333838 or complete our online contact form and we will be in touch as soon as possible.