It gets hell hot in Arkansas, but the humidity is what really kills you. However, a fully perfed suit will work up to about 95*F as long as you keep moving and air flowing. Anything above that and I use a Marsee hydroweave cooling vest, which you soak in water and functions as a cooler under your leathers. Again, you have to keep moving, but it is really effective.
Full 1 pc black leathers
Sidi vortice air
It sounds hot but when riding it's fine imo (used it in south of france for 3 days on the track with upto 40 degrees C ).
When just going on a short trip I use my normal low shoes, regular jeans, full face helmet (black usually), leathers gloves and a textile jacket with the isolation stuff taken out. Got some comments from the police the other day for not using boots/armored pants (got a ride home from them after my laverda died on me at 4 AM )
+1 on having something under your leathers in the heat, really helps with taking your gear off for a bit.
I ride in my short and t-shirt - UNDER my Olympia Stealth if it is really hot or my Olympia Phantom if it isn't too hot or I think it might rain. When the vents are open and you are moving, it is pretty comfortable. I also wear either my Sidi Doha's or Vertigo Airs. Finally I have a perf'd A-stars set of leathers that I wear if I am going out and feel my self control may not be the best. None of them are too bad in the heat unless I am in the leathers and have to stop somewhere. Then I always think about that Geico caveman commercial and how stupid those guys look in their leathers off their bike. I usually get back on the bike and run that errand later in my truck.