Why You Need to Check Tire Pressure More Often During Cold/Wet Weather

You managed to maintain your tire pressure constant throughout the year. But come December and the accompanying cold and wet weather, you're faced with your tire pressure light coming on constantly, even when you've recently checked it. What gives?

Lower weather temperature causes TPMS to react

The drop in temperature is actually to blame. Temperature changes affect the air pressure in your tires. While a hot environment causes the air inside your tires to expand and over-inflate, cold weather causes the air inside the tires to contract and under-inflate. For cars that come with a tire pressure monitoring system (TPMS), this can be problem because you could end up seeing your TPMS lighting up frequently.

The good news is that the issue isn’t dangerous. When the TPMS light comes on, your car's computer is simply telling you that you need to add air into your tires. Usually, your tire pressure will decrease about 1 pound per square inch (PSI) for every 12 degree Celsius drop in the environmental air. On the contrary, it will increase about 1 PSI for every 12 degrees that the outside temperature rises.

Though it's nothing serious, it's imperative that you adjust your tire's pressure nonetheless. With incorrect tire pressure, you'll experience lower fuel efficiency and more frequent gas stops. Meanwhile, the correct tire pressure can improve gas mileage, so do yourself a favor and top up that tire pressure.

Check tire pressure regularly

Every vehicle manufacturer lists a recommended tire size and inflation pressure on the vehicle's tire information plate (usually located somewhere on the door frame on the driver side) or in the owner's manual. However, even if the car owner follows these recommendations, the actual pressure in the tire can vary significantly due to factors such as weather.

Often, the TPMS will light up in the morning when it's coldest. The light may disappear as the temperature warms, but it's still likely that tire is still under-inflated. This is why it's important to check the pressure in your tires regularly when the weather turns cold.

You should check your tire pressure at least once a month. It should be noted that some TPMS will not alert you until the tire is severely under-inflated, in which case it could become dangerous. Get to know your car's TPMS, and depending on its temperament, you may want to check your tire pressure more frequently.