i keep mine around 29-31, always fluctuates a bit.
i plonk all my snakes in a bucket or lukewarm water occasionally, sometimes they submerge everything except their noses for a while (sooo cute!!), sometimes they get straight out,..they always shed perfectly.
are you keeping them outside so they have access to sunlight for heat?
or just inside with no heat?
i guess on the hot days thats ok but really they should have a bit more heat to help aid digestion as they need a temp of 28 degrees to function properly. also uv is a benefit even though people might not agree i think it is imperative the a healthy diamond.