Gritters are being deployed on UK roads this week, but not for snow. As the Met Office issues a rare red weather warning for extreme heat, with temperatures forecast to reach 40°C, motorists are being warned that the sun can be just as hazardous as ice. The AA says that in extreme heat, road surfaces can soften or become sticky, and heavy traffic can even cause them to rut. This can affect braking, steering and grip, especially for motorcyclists and cyclists. The RAC expects breakdown callouts to be around 20% higher than a typical late-June Monday, as vehicles overheat and tyres fail.
The basics are simple: the UK is facing an exceptional heatwave. The Met Office has issued a red warning for extreme heat covering central parts of the UK from Wednesday until Thursday evening, with an amber warning in force across a wider area from Monday to Thursday. The red alert means there is a risk of serious illness or danger to life for the entire population, not just the vulnerable. For drivers, the key dangers are vehicle breakdowns, damaged road surfaces, and the risk of leaving passengers or pets in hot cars.
“Why UK drivers face gritters and breakdowns in extreme heat, with safety tips from the AA and RAC.”
Why does this happen? The UK’s infrastructure is not built for extreme heat. Road surfaces, particularly asphalt, can soften when temperatures exceed 30°C, leading to deformation under traffic. Vehicles that rely on cooling systems designed for milder climates can overheat quickly. Many cars do not have effective air conditioning, and tyres that are under-inflated, damaged or old are more likely to fail in hot conditions. The current UK temperature record is 40.3°C, set in July 2022, and this week could see that equalled or broken.
For UK readers, the practical impact is significant. If you are driving during the red warning, you face longer waits for breakdown assistance as patrols are likely to be prioritising the most urgent jobs. The RAC advises postponing non-essential journeys if your car lacks effective air conditioning, especially if you are travelling with vulnerable people like young children or older adults. Even on amber-warning days, the AA says you should check tyre pressures, tread and sidewalls before a long journey, and carry water in case you are delayed. Gritters may be out spreading salt or fine aggregate to help improve grip on softening surfaces, so do not be surprised to see them in summer.
Q: Should I drive in a red heatwave warning? Only if your journey is essential and your vehicle has effective air conditioning. The RAC says drivers without working AC should postpone trips until warnings are lifted or travel during cooler times of day.
Q: Why are gritters on the roads in a heatwave? Gritters can be deployed to spread salt or sand onto softening road surfaces to help provide grip and prevent rutting. The AA warns that patches of road can become tacky or uneven, affecting braking and steering.
Q: What should I pack in my car for a heatwave? An emergency breakdown kit including water, an umbrella for shade, and a phone charger. Check tyre pressures and coolant levels before setting off, and never leave pets or people unattended in a parked car.
What happens next depends on how high the mercury climbs. The Met Office red warning lasts until 9pm on Thursday, and if the 40.3°C record is broken, it could prompt more widespread transport disruption. The UK Health Security Agency has issued its second ever red heat health alert, meaning a rise in deaths is likely. For drivers, the immediate priority is to stay safe, stay hydrated, and be prepared to wait longer for help if you break down.