While you are checking the air pressure on each tire, viusally inspect the tire's tread and sidewalls for wear and road debris that may have penetrated your tire.
Tires depend on good tread condition to maintain traction and to shed water on wet roads.
Tread depth should be checked for excessive and uneven wear. The more tread the tire has remaining, the higher the reading will be. Uneven readings indicate improper tire inflation or the need for a wheel alignment. You may also see wear indicators, thin bald strips, revealed across two or more treads. Replace these tires immediately.