Originally Posted by
JoeyBike
... Zero humidity would be awesome for evaporation. Which of course is the problem!
There probably have been studies done on that, all of which I am unaware. But my experience is that very low humidity is preferred because your sweat evaporates quickly while it is on you, thus you got some productive cooling from the sweat evaporating.
But when I have been in very high humidity (dewpoints over 70 degrees) much of your sweat drips off of you, which provides no cooling and also the sweat that did not drip off of you won't cool your skin below the dewpoint.
But seeing where you are located, you know more about high humidity than I do.