Heating problems

[Weather1]

The warm end of my enclosure hovers around 85. However the cold end is only 62.

The thermometers are lying on the substrate. I have an UTH and a heat lamp. 27 gallon = 30" long

I keep corn snakes.

Any suggestions on how to warm up the cool end a bit?

Or is 62 ok for the cool end

Thanks for the advice