Heat Is the Enemy of Tires
While winter driving gets most of the tire safety attention, summer heat actually causes more tire failures. The combination of hot ambient temperatures, scorching pavement, and the heat generated by driving creates conditions that push tires to their thermal limits. Road surfaces can reach 150 degrees Fahrenheit or more on a sunny summer day, and your tire's internal temperature adds another 30 to 50 degrees on top of that. Understanding how heat affects your tires helps you take preventive action during the hottest months.
How Heat Affects Tire Pressure
Air expands when heated, and the air inside your tires is no exception. For every 10-degree Fahrenheit increase in temperature, tire pressure rises approximately 1 PSI. This means tires inflated to the correct 35 PSI on a cool morning could read 39 or 40 PSI by afternoon on a hot day. While this normal fluctuation is accounted for in tire design, starting with already-overinflated tires can push pressures into dangerous territory during hot weather driving.
The Overinflation Trap
Some drivers, aware that heat increases pressure, intentionally underinflate their tires in summer thinking the heat will bring them up to the correct level. This is a dangerous mistake. An underinflated tire on hot pavement generates excessive internal heat from sidewall flexing, dramatically increasing the risk of a blowout. Always inflate to the door placard specification when the tires are cold, and let normal temperature-related pressure increases take care of themselves.
Rubber Degradation in Heat
High temperatures accelerate the chemical breakdown of tire rubber. The antioxidant compounds that protect the rubber are consumed faster in hot weather. UV radiation from the sun further degrades the rubber surface, promoting dry rot and cracking. Tires that spend long hours parked in direct sunlight — in parking lots, driveways, or on the street — age faster than those garaged or shaded.
Summer Blowout Risk
The NHTSA reports that tire-related crashes peak during the summer months, particularly from May through October. The combination of heat, long road trips, and heavily loaded vacation vehicles creates ideal blowout conditions. Underinflation is the primary trigger — the added heat of summer pushes an already-stressed, underinflated tire past its failure point.
Hot Weather Tire Care Tips
Check tire pressures at least twice a month during summer, and always before any long trip. Check when the tires are cold — first thing in the morning or after the car has been parked for at least three hours. Inspect tread depth and condition more frequently in summer, as heat accelerates wear. Park in shade or a garage whenever possible to reduce UV exposure and keep the tires cooler.
Driving Adjustments
On extremely hot days, consider reducing your highway speed by 5 to 10 mph to reduce heat generation. Take breaks every two hours on long drives to let the tires cool. Avoid driving on bald or nearly bald tires — thin tread provides less insulation between the hot road surface and the tire's internal structure. If you notice a vibration, pull, or unusual noise, stop and inspect your tires promptly.
Choosing Summer-Ready Tires
If you're replacing tires for summer, look for models with high-temperature ratings. The UTQG temperature grade (A, B, or C) indicates how well the tire dissipates heat. Grade A tires handle heat best. Tires with higher speed ratings are also engineered for greater heat resistance. Browse Ship.Tires to find tires with top temperature ratings that will keep you safe through the hottest months of the year.