I came across one vehicle manual that states that the listed tyre inflation pressures are based on ambient temperature of 20 deg C.
For every 10 deg C, add 0.1 bar.
So for example, the recommended tyre pressure for my car is 250 KPa or 2.5 bar.
For our climate of average 33+ deg C, I 'll have to add 0.2 bar. That will be 2.7 bar.
Usually, when I inflate to 2.5bar, the front tyres seem to have more flabs.
At 2.7 bar, it resembles the properly inflated tyre picture from the manual.