Driving in a Heatwave: Hot Weather Driving Tips for Scottish Drivers

When people picture dangerous driving conditions in Scotland, they usually picture ice, fog, and driving rain. Warm weather brings its own set of risks, and they catch drivers out precisely because nobody is expecting them. From tyre blowouts to sun glare on the A9, here is what to watch for when the temperature climbs.

Scotland does not see heatwaves as often as the rest of the UK, but when one arrives, usually a few days of unbroken sunshine and unusually high temperatures, the roads change fast. A car that has been fine all year can develop a fault in a single hot afternoon, and the first hot weekend of the year reliably brings a surge of extra traffic and extra accidents as everyone heads outdoors at once.

Heat makes the air inside your tyres expand, and hot road surfaces raise the temperature of the rubber itself. An underinflated tyre flexes more as you drive, builds up heat faster, and is far more likely to suffer a blowout at speed. Check your tyre pressures, including the spare, when they are cold, ideally before a long journey rather than relying on a reading taken straight off the motorway.

Check tread depth too. Worn tyres lose grip on hot, softened tarmac just as they do on a wet road, and a blowout on a fast road like the M8 or M74 in heavy summer traffic is a genuinely dangerous situation, not just an inconvenience.

The first spell of proper sunshine each year brings noticeably heavier traffic to the Central Belt, particularly on the motorway network around Glasgow and Edinburgh, as people head out for the day rather than commute to work. Heavier traffic means more stop-start driving, and stop-start driving in heat is exactly the combination that overworks tyres and engines alike. Building in a few extra minutes and a bit of extra following distance goes a long way.

Engines work harder to stay cool in hot weather, especially in stop-start traffic. Before a long drive, check your coolant level when the engine is cold and top up if needed. If the temperature gauge starts climbing towards the red, pull over somewhere safe and let the engine cool down rather than pushing on and risking a breakdown on a fast road.

Air conditioning keeps you comfortable, but it also puts extra load on the engine. If you notice the temperature gauge creeping up while sitting in slow traffic with the air con on, easing off it for a few minutes can help.

A low evening sun is one of the most underrated hazards on Scottish roads in summer. Long north-south routes like the A9 between Perth and Inverness can leave you driving almost directly into the sun for extended stretches, particularly in the early morning and early evening when it sits low on the horizon.

Keep a clean windscreen, a dirty one scatters light and makes glare worse, keep sunglasses in the car, and drop your visor before you need it rather than after you have already lost sight of the road ahead. If the glare becomes genuinely blinding, slow down and increase your following distance.

Dehydration affects concentration and reaction times in much the same way tiredness does, and it creeps up on you quietly. Keep water in the car on longer journeys, especially if you are heading to the coast for the day. Ayr, Troon, and Loch Lomond all see a lot of extra traffic on the first genuinely warm weekend of the year, so factor in proper breaks.

A hot car is also a sleepy car. If you are driving with the windows down or the air con on to manage the heat, do not let the warmth lull you into pushing on when you are tired. Pull in somewhere safe if you need to.

Summer heat often arrives alongside high pollen counts, and a lot of over-the-counter hay fever medication causes drowsiness. Some antihistamines are labelled non-drowsy, but not all are, and it is worth checking the packet rather than assuming, particularly with a new brand or a higher dose than usual.

If a medicine causes drowsiness, that is not a minor side effect behind the wheel. It carries the same kind of risk as driving while tired, and it can affect your insurance if you are involved in an accident while impaired.

If you are trying a hay fever tablet for the first time, test it on a day you are not driving before relying on it for a long journey. Everyone reacts differently, and the effect can be stronger than the packaging suggests.

Older or poorly maintained tarmac can soften and bleed in sustained heat, when the bitumen binder rises to the surface, and this reduces grip significantly, particularly under braking. It happens more often on rural single-track roads in the Highlands and on older estate roads than on well maintained trunk routes, but it can catch out any driver expecting a normal dry road surface.

If a road surface looks shiny or sticky, or has visible tar bleeding through, treat it with the same caution you would show on a wet road. Leave extra stopping distance and avoid harsh braking or sharp steering inputs, and take corners a little more gently than usual until you know how the surface is behaving.

Warm, dry weather brings a lot more motorbikes and bicycles onto Scottish roads, from daily commuters to weekend riders heading out to Loch Lomond or the Trossachs. Motorbikes are smaller and harder to judge speed and distance for than a car, and cyclists are more vulnerable again.

Take an extra look before pulling out of a junction or overtaking, particularly on routes popular with weekend riders, and give cyclists the space required by law when passing. A moment's extra care at a junction costs you nothing and can prevent a serious injury.

A car parked in the sun heats up far faster than most people expect. The temperature inside can climb sharply within minutes, even with a window cracked open. Never leave a child or a pet in a parked car in warm weather, even for what feels like just a couple of minutes while you run into a shop.

If you see a child or an animal in obvious distress in a hot car and the owner cannot be found, call 999. It is far better to act and be wrong than to walk on and be right.

Heatwave weekends mean more cars on the road, more day-trippers unfamiliar with the route, and more tired, dehydrated drivers all at once. That combination leads to more accidents. If you are involved in a collision, the steps to take are the same whatever the weather: stop, check for injuries, exchange details, and report the accident to Police Scotland where required. Our guide on what to do after a car accident covers this in full.

You can start a claim online once you are safely off the road, or if you need help right now, use our emergency line and we will take care of the rest.