I can't believe you get it running that cool when it's that hot an humid. I'm in Northern Illinois and when it's 80degrees and 90% humidity, I don't even bother. If I try to richen it to cool it, it gets so rich that it won't run. If I tune it to run, my temps scream up to 300... stupid midwest!
I have noticed though, my OS 21 RG doesn't care what the weather is like, I can tune it to stay under 250 with good performance even if it is 90 and 90. But with my Omega 21 Comp, it has to be below 80 degrees and less that 50% humidity to keep the temps below 260. Those are fun days though, that engine really rips. To bad it's so picky.