I love my boostmonkey, but he prefers cooler climes as well. On a hot (and let's not forget humidity as a factor too!) I will see a change as much as 1-1.5psi lower than my "normal settings." I like the monkey because I know I will not be increasing the boost much beyond 16 psi (because I'm a wuss!) So he's been working fine, and being able to adjust it from within the cabin for $100 (I got mine used) it's been wondrous for the both of us.
and he's got LED's too!!!
imagine that -- LED's!!! BLING BLING YO!!!