How to Keep Your Car Running Well in the UK Heatwave
To keep your car running well in hot weather, check your coolant, tyres, battery and air conditioning before any journey. Travel during cooler parts of the day, park in the shade, and carry an emergency kit with plenty of water. These simple steps help prevent overheating, blowouts and breakdowns during extreme heat.
The UK is sweltering. The Met Office has issued a rare red extreme heat warning for June 2026, with temperatures forecast to reach up to 38°C in parts of England and Wales. Warnings like this are uncommon, and they carry real risk for both people and vehicles.
Hot weather puts your car under serious strain. According to the RAC, breakdowns are expected to rise by up to 20% during this heatwave, with drivers warned to expect longer waits for recovery as patrols deal with the surge. Engines overheat, batteries fail, and tyres blow out far more often when the mercury climbs.
The good news? Most heat-related breakdowns are preventable. This guide from D&M Coachworks walks you through the practical checks that keep your car cool, safe and reliable when the temperature soars.
Why do cars break down more in hot weather?
Cars are designed to operate within a certain temperature range. When outside temperatures climb into the mid-30s, several systems get pushed beyond their comfort zone at the same time.
The RAC reported breakdowns surging by up to 20% during the June 2026 heatwave, with road safety spokesperson Rod Dennis warning that this could be a "record-breaking" June for both temperatures and breakdown volumes. The most common culprits are:
- Overheating engines, often caused by low coolant or failing radiators
- Battery failure, as heat speeds up the chemical wear inside the battery
- Tyre blowouts, since hot tarmac and high air pressure put extra stress on rubber
- Air conditioning faults, which leave drivers and passengers dangerously hot
Knowing the weak points helps you check the right things before you set off.
How do I stop my engine from overheating?
Overheating is one of the most frequent hot-weather breakdowns, and it can cause expensive engine damage if ignored.
Start by checking your coolant level. With the engine cold, look at the expansion tank and top up if the level sits below the minimum mark. Use the correct coolant or antifreeze mix for your vehicle, as plain water alone is not enough.
Next, inspect the hoses and radiator for leaks, cracks or soft spots. If you spot any signs of damage, get them looked at before you drive in the heat.
While driving, keep an eye on your temperature gauge. If it climbs towards the red zone, turn off the air conditioning, switch on the heater to draw heat away from the engine, and pull over safely as soon as you can. Never remove the radiator cap while the engine is hot.
How does hot weather affect car batteries?
Most drivers associate flat batteries with winter, but summer is just as hard on them. Heat speeds up the chemical reactions inside a battery and accelerates wear, which means a battery that struggled through a cold winter may give up entirely in a heatwave.
If your battery is more than three years old, it is worth having it tested. Watch for warning signs such as slow engine cranking, dim headlights, or dashboard warning lights. A quick check now is far cheaper than a roadside breakdown later.
How do I check my tyres in hot weather?
Tyres take a beating during a heatwave. Hot road surfaces combined with high internal pressure increase the chance of a blowout, particularly on motorways.
Check your tyre pressure when the tyres are cold, and match it to the figures in your owner's manual or the sticker inside the driver's door. Do not let air out of warm tyres after a long drive, as this can leave them underinflated once they cool.
Inspect the tread depth too. The legal minimum in the UK is 1.6mm, but more tread gives you better grip and heat resistance. Look for bulges, cracks or embedded objects, and replace any tyre that looks worn or damaged.
What should I do if my car has no air conditioning?
The RAC's advice during the red warning was clear: drivers whose vehicles lack effective air conditioning should strongly consider postponing non-essential journeys until temperatures drop.
If you must travel, plan around the heat. Drive early in the morning or later in the evening when it is cooler. This matters most when you are carrying vulnerable passengers, including young children and older adults, who face greater risk from intense heat.
If your air conditioning is blowing warm air or smells unpleasant, it may need re-gassing or servicing. A working air conditioning system is not just about comfort during a heatwave. It keeps drivers alert and reduces fatigue on long journeys.
What should I pack in an emergency car kit?
Even with careful preparation, breakdowns happen. With recovery waits likely to be longer during the heatwave, a well-stocked kit keeps you safe while you wait. The RAC recommends:
- Plenty of water and soft drinks
- A cool bag or box to keep drinks cold
- A blanket or jacket to cover hot seats
- Sun protection, including a hat and sunscreen
- A fully charged phone and a portable charger
Park in the shade wherever possible, and if you do break down, wait in a shaded spot away from traffic rather than inside a hot vehicle. Never leave pets inside a parked car, as temperatures can become fatal within minutes.
Protecting your car beyond the heatwave
Hot weather does more than risk a breakdown. Intense sun can fade and crack paintwork, while heat-related faults can lead to bodywork damage if a minor incident occurs on a busy summer road.
If your vehicle picks up scrapes, dents or paint damage this summer, prompt repair stops small problems from becoming costly ones. D&M Coachworks provides high-quality car body repairs, insurance claim repairs and fleet management for drivers and businesses across the UK, working with all makes and models of cars and vans. You can explore our services to keep your vehicle looking and performing its best long after the heatwave passes.
Stay cool and stay safe on the roads
A heatwave like the one forecast for June 2026 is a genuine test for any vehicle. By checking your coolant, battery, tyres and air conditioning, travelling during cooler hours, and packing an emergency kit, you give your car the best chance of getting you where you need to go without trouble.
Take the Met Office warnings seriously, postpone non-essential journeys where you can, and look after both yourself and your vehicle. A few minutes of preparation today could save you a long, hot wait at the roadside tomorrow.
Frequently asked questions
What temperature is too hot to drive a car?
There is no single cut-off, but the risk of breakdowns rises sharply once temperatures reach the mid-30s. During the June 2026 red warning, with temperatures forecast up to 38°C, the RAC advised drivers without effective air conditioning to postpone non-essential journeys altogether.
How often should I check my coolant in summer?
Check your coolant level at least once a month during hot weather, and always before a long journey. Top up with the correct coolant mix when the engine is cold if the level falls below the minimum mark.
Can hot weather really cause a tyre blowout?
Yes. Heat raises the air pressure inside a tyre, and combined with hot road surfaces this puts extra stress on the rubber. Underinflated or worn tyres are most at risk, so check pressure and tread before driving in a heatwave.
Why does my car battery fail more in summer?
Heat accelerates the chemical wear inside a battery, which shortens its life. A battery weakened over winter often fails completely in summer heat. If yours is more than three years old, have it tested before extreme weather hits.
Where can I get my car repaired after summer damage?
D&M Coachworks offers car body repairs, insurance claim repairs and fleet management in Epsom and surrounding areas. You can find details of all our services at dandmcoachworks.co.uk.