It seems like most people do this in the opposite direction when they need more humidity, but if you make sure your water dish isn't over the top of your UTH it wont heat the water and might effect it. How much so I don't know.

One thing I noticed is my humidity spikes way up there if the substrate is damp at all. Make sure that your snake hasn't slithered through the water or splashed any onto the substrate. It seems to make a huge difference in my tank.

GL xD