I don't bother checking the ambient humidity either. There's a humid hide, moistened daily, the rest of the enclosure is the same as whatever the house is at. In winter it's a bit lower, because winter temperatures and the furnace heating cause it to be lower, but I do know it's generally around 25-35%. In summer the ambient humidity is naturally higher, varies with rain or dry spells.
They're okay with the general house humidity that's available, the hide box is there if they need it higher.