I think you're on to something here. I don't have humidity, but I've noticed that my fuel economy goes way down when I'm riding in 90°+ days, versus days when the temperatures are in the 70's or 80's. I think that the temperature compensation for these carbs isn't as good as, say, the carbs on my Ninja. In temps over 90°, I also have to be very careful to keep the bike from stalling at idle, which is never a problem in the cool of the morning.
Hmmm, I with the lack of accurate temperature compensation, I wonder of rejetting might not leave me too lean in the mornings? I have a feeling that Oregon mornings are a lot cooler than Florida mornings. This morning was 54°, for example. (The only part of Florida I lived in was Pensacola and Gulf Breeze, and in the summer I woke up wondering if
it would ever cool off again.

For an Oregon boy, that was mighty hot. Swimming in the Gulf after work was mighty nice, though.)
Scott