Tire pressure changes about 1 psi (pressure per square inch) for every 10 degrees Fahrenheit change in temperature. For the best handling and most fuel efficient, and therefore, most air friendly driving, adjust your tire pressure accordingly. A big change in the weather could mean your tires are over or under inflated. In the winter months, it’s likely your tires are a little low.
Check your owner’s manual for the correct pressure. The recommended pressure is the cold tire inflation pressure, so you’ll need to check your tires before you drive. If your car is in a heated garage, adjust the pressure up 1 psi for every 10 degrees difference between the temperature in the garage and the colder outside air.
For more detailed information on changing tire pressures, see this Tire Tech article