Yeah humidity is a killer. Dry heat I can take but I struggle with the humidity as well. I now live in Hong Kong where it rarely gets lower than 70% humidity for 6 months of the year. With temps in the low to mid 30's its a hard life if you want to get out on the bike.

Still do it though cause I love it. Carry two water bottles and a 1.5L camel back to ward off dehydration. Its a bummer to carry so much extra weight but better than the alternative.