Tire pressure decreases in colder temperatures due to the fundamental relationship between gas pressure, volume, and temperature, as described by the Ideal Gas Law. When the temperature drops, the air molecules inside the tire move slower and collide less frequently with the tire walls, resulting in reduced pressure. This phenomenon is not a leak, but a natural physical process. For example, a tire inflated to 35 psi at 70F (21C) could drop to 30 psi at 32F (0C).
Understanding this temperature-pressure relationship is crucial for vehicle safety and optimal tire performance. Properly inflated tires ensure even tread wear, improve fuel efficiency, and provide better handling and braking. Historically, this phenomenon became increasingly relevant with the widespread adoption of pneumatic tires in the late 19th and early 20th centuries. As vehicles became more common in diverse climates, the effect of temperature on tire pressure became a practical consideration for drivers.