Help understanding enclosure temps

I apologize in advance if this is a very stupid question. I am preparing my enclosure for my first ball python(arriving in a few weeks) and I am having something of a hard time understanding the temperatures I need to have. I understand that the hot spot needs to be 90F. My ambient temps are 80-85F. The issue(?) is that the surface temps on the cool side read as low as 71F in some places on the cool side. The ambient is still 80, warmest spot on hot side is 91F. I am heating with an RHP. Are my cool side surface temps going to be a problem??

I have 1 ball python that is housed around the same ambient temps as yours and he does fine. If you can get the temps to 75 on the cool side, that is most ideal.