Since I installed TPMS on my F6B I've been surprised at how much the pressure increases at high speeds on hot days. I run my rear at about 44 PSI, but that often increases to over 50 while riding. At very high altitudes the pressure gets even higher due to the drop in atmospheric pressure.

The same goes for the temperature. The front tire stays just a few degrees above the ambient temperature, but the rear often exceeds 130 degrees.