A tire monitor and a tire pressure gauge for reading the data from the tire monitor are disclosed. The tire monitor includes an in-tire controller that stores a target inflation pressure representing the pressure to which the tire should be inflated when the tire is at a standard temperature. The tire monitor transmits the target inflation pressure to the external processor when the external processor is connected to the in-tire monitor over a communication link. A sensor array in the tire monitor can provide pressure and temperature readings that are stored in the monitor and used to provide a temperature-compensated fill pressure for the tire. The tire pressure gauge provides the user with a fill pressure to be used in inflating the tire. The tire pressure gauge communicates with the tire monitor and obtains pressure and temperature readings stored in the tire monitor. These reading are used to provide the temperature-compensated fill pressure.