Mike, I've worn my 9 yard 16 oz heavyweight handsewn when the temp has been in the nineties and the humidity was in the 30-40% range,as well as a couple times when it was 90% plus humidity after a monsoonal downpour. Was very comfortable as long as I didn't stay in one place to long. The only bad part was my head gear, I was wearing a Pith helmet and that was damn hot(don't ask, it was my birthday ) When your moving the pleats create airflow, the only place that gets a lot of heat buildup is around your middle.

Rob Wright