What are the average humidity levels at the moment?

I would just look for any abnormalities at all on the belly - if you can, take a pic of the belly how it is now and just do regular checks and compare. If there's anything unusual (discoloration, redness around particular scales, lumps or bumps) then you'll know.

On a side note: pllleeeaaaseee post pics of you setup! I am dying to see it; it sounds awesome!