Agreed the temps are low the warm spot (90ºF does not feel HOT to us humans so I like to say warm spot as some misunderstand hot is referring to snake temps not ours and decide that 120º feels right...) A small increase her would help a touch but low 70s are more of a concern they need to be warmer I would guess that the ambient AIR temp (not surface) is also low. It should be around 80º as well give or take a couple of degrees.

What are you using to measure temps with? Where are you measuring them?