what type of bedding are you using ... bedding could make a difference as well ... i have a 55 gal tank with my 2 in it my hot side stays 92-95 and i use a under tank heater and a 100w infra red bulb... and my cool stays around 80-82 and i dont have anything covering my screen top and my humidity avaerages between 60-65% ... i use aspen snake bedding from zoo med
P.S .. i also have the water bowl placed dead center of tank that way half the water stays on the uth and the other dont this could help with my humidity as well