What counts is the temperature of the rubber that is not allowed to go over a sertain temperature.
The tire is warmed up bij the deflection and flexing back of every segment of it, about 10 times a second at 65m/h. The higher the speed the more heatproduction a nd the more deflection also more heatproduction a cycle.
Cooling down is dependent on temperature differences between rubber and in- and outside- air . so inside air temperature so is in a way related to the temp of rubber.
But your pressure risisng could be explained that high because it was measured riding 65m/h at an ambiënt temp of 100degrF+, while they where filled at 85psi at an abiënt temp of 65 degrF.
Will give a list I made , where the advice pressure fat printed at 65degrF.
Then you can see what 105 psi will give for inside tire temperature.
Estimate that if tire inside gets about 115 degr if ambiënt temp is 65 degr F, when driving about 55m/h.
Then I read in my tabel that 85 psi filled at 65 degr F, gets 50 degrm hotter, then when ambiënt temp is 100 degr F , tire inside will sertainly not get hotter then 145 degr F . 140 is hottest in my tabel.
Then it reads about 99 psi, so 105 for 65m/h can be OK.
End conclusion from me , for what its worth, you most likely have the right pressure for your weight and speed.
