Summer Tire Pressure: Why You Should Check Tires When They’re Cold
No, you should not let air out of your tires just because the pressure reads higher on a hot day.
Tire pressure naturally increases as tires warm up, especially after driving on hot pavement. If your tires were inflated correctly when cold, that higher reading is usually a normal result of heat, not a sign that you need to release air.
Letting air out of a warm tire can leave it underinflated once it cools down. Instead, check and adjust your summer tire pressure before driving or after your vehicle has been parked for at least three hours. Always use the recommended cold PSI listed on the driver’s-side door placard or in your owner’s manual.
Why Does Tire Pressure Increase in Hot Weather?
Air expands as it warms. As the outside temperature rises and your tires heat up from driving, the air inside them gets warmer and tire pressure increases.
Tire pressure may change by approximately 1 to 2 PSI for every 10°F change in temperature. The exact change can vary depending on the tire, vehicle and driving conditions, but some increase during hot weather is expected.
Driving also creates heat as the tires flex against the road. That means a tire checked after a highway drive may show a noticeably higher reading than it did before you left.
Your tires are not asking for a summer air-pressure haircut. They are simply warm.
Does a Higher Hot Reading Mean My Tires Are Overinflated?
Not necessarily.
A tire that reads above the vehicle’s recommended PSI after driving is not automatically overinflated. The recommended pressure on your vehicle’s placard is a cold tire pressure, so it should be compared with a reading taken before driving or after the vehicle has been parked for at least three hours.
For example, suppose your door placard recommends 35 PSI and your tire reads 39 PSI after a long drive. Do not immediately release air. Let the tires cool, check them again and make any adjustment based on the cold reading.
You should also avoid using the pressure printed on the tire sidewall as your target. The sidewall number represents the maximum pressure the tire can hold, not the recommended operating pressure for your specific vehicle.
Why Underinflation Is a Bigger Summer Concern
Releasing air from a hot tire can create a different problem once the tire cools: underinflation.
An underinflated tire flexes more as it rotates. That extra movement generates heat, increases wear and places additional stress on the tire. Summer driving conditions, including high temperatures, heavy loads, road trips and extended highway speeds, can add even more heat.
The National Highway Traffic Safety Administration identifies underinflation as a leading cause of tire failure and recommends checking tire pressure regularly when the tires are cold.
Underinflation can also affect:
- Handling and steering response
- Tire wear
- Fuel consumption
- Ride quality
- The tire’s ability to carry the vehicle’s intended load
The safest approach is not to guess based on how the tire looks or how hot the day feels. Use a reliable pressure gauge and follow the vehicle manufacturer’s cold PSI specification.
How to Check Summer Tire Pressure Correctly
Follow these steps for a more accurate reading:
- Check before driving. Check the tires first thing in the morning or after the vehicle has been parked for at least three hours.
- Find the recommended PSI. Look for the tire information placard inside the driver’s door or consult the vehicle owner’s manual.
- Check all four tires. Use a reliable tire pressure gauge and record the reading for each tire. Check the spare tire too, when applicable.
- Adjust according to the cold specification. Add or release air only when needed to match the vehicle manufacturer’s recommendation.
- Replace the valve caps. Valve caps help keep moisture, dirt and debris away from the valve.
We recommend checking tire pressure at least once a month and before long trips, carrying heavy loads or towing a trailer.
Additional Summer Tire Safety Tips
Correct air pressure for tires in summer is important, but it should be part of a broader tire-maintenance routine.
Check your tires for:
- Cracks, cuts, bulges or other visible damage
- Uneven or excessive tread wear
- Objects lodged in the tread
- Signs of aging or deterioration
- A tire pressure warning light that returns after inflation
These checks apply whether your vehicle uses all-season, all-terrain or summer tires. No tire type gets a free pass when the temperature climbs.
Frequently Asked Questions About Summer Tire Pressure
Should I let air out of my tires when it’s hot?
No. Do not let air out simply because your tires show a higher pressure after driving in hot weather. Tire pressure normally increases as the tires warm. Recheck the pressure when the tires are cold before making an adjustment.
How does temperature affect tire pressure?
Tire pressure increases as the air inside the tire gets warmer and decreases as it cools. Pressure may change by approximately 1 to 2 PSI for every 10°F change in temperature.
Why does tire pressure increase in hot weather?
Warm air expands. Higher outside temperatures, hot roads and heat generated while driving all warm the air inside the tire, causing its pressure to rise above the cold reading.
Is it safe to drive with overinflated tires in summer?
A tire that is truly overinflated when cold should be adjusted to the vehicle manufacturer’s recommended PSI. However, a higher reading taken immediately after driving does not necessarily mean the tire is overinflated. Allow the tires to cool and check them again before releasing air.
How much should I reduce tire pressure on a hot day?
You should not reduce tire pressure by any set amount simply because the weather is hot. Adjust the tires only according to the manufacturer’s cold PSI specification. Letting air out while the tires are warm could leave them underinflated later.
Keep Your Summer Tire Pressure in Check
Summer heat does not mean you need to constantly add or remove air. It means you need to check tire pressure at the right time.
Measure pressure when the tires are cold, follow the PSI listed on your vehicle’s door placard and check it at least once a month. A few minutes with a pressure gauge can help your tires wear more evenly, handle more consistently and avoid unnecessary heat buildup.
Not sure whether your tires are ready for the heat? Tire Discounters offers free inspections and free tire pressure refills to help you stay prepared for summer driving.
