Tire's maximum inflation pressure is branded on tire sidewall near the bead close to the wheel, usually measured in kilopascals (kPa) and pounds per square inch (psi).
For some tires maximum inflation pressure may be higher that their assigned maximum inflation pressure based on tire load range. For example, maximum tire inflation for a P-metric sized tire with Standard Load range is rated at 35 psi, but many P-metric sized tires are branded with maximum tire inflation of 44 psi to accommodate any unique performance requirements determined by the tire and vehicle manufacturers.
Maximum inflation pressure of a tire is the highest "cold" air pressure the tire is designed to be inflated to support its maximum load as designated by tire manufacturer. "Cold" tire pressure means the tire has not been driven for some time and has not generated heat that would have caused the temporary tire pressure increase. Maximum inflation pressure is not necessarily the recommended tire pressure for your vehicle, so always refer to your vehicle's tire placard or owner’s manual for recommended tire pressure settings.
If your vehicle was parked in the sun or has been driven extensively during the day, your tire pressure will be "hot" and can show up to 4 to 5 psi above the recommended "cold" pressure levels. Sometimes it might go above the tire's maximum inflation pressure stamped on tire sidewall. Remember that this extra "hot" tire pressure is temporary and if the "cold" tire pressure was initially set to proper inflation levels, the temporary "hot" air pressure will return to recommended levels as tires cool off.