I know having a super-grippy pole might sound great, but trust me, it's really not. The friction on my pole is sometimes so excessive that I get terrible pole burn, even on my hands, from almost any spin I try--even something as basic as fireman. Spins like the front hook spin with it's POC on the lower-thigh and upper-calf feel great as well. Also, I didn't realize how many moves involve sliding my body or hands against the pole until I started sticking like crazy. Superman? Thighs slide around and then down the pole. Apprentice to extended butterfly? Bottom hand slides down the pole a few inches. I can still execute these moves, but doing so is considerably more awkward than when the pole is less grippy. And since the room I'm in is also hot, my torso gets very sweaty and I have to keep it away from the pole unless I want to go from excessive friction to no friction at all.
I don't understand the physics/chemistry of it, but in my experience there seems to be a certain range of humidity that results is a lot of friction between one's skin and chrome poles (brass poles as well, but my experience with them is more limited). Above or below that range, it seems like friction is lower (and hence poles less "grippy"). My guess is that humidity is not the single determining factor, the particular dancer's skin probably plays a role in this too, as well as, the temperature of the pole and the room. Most likely there is some sort of complex interaction between these variables (and possibly others) that put you over the edge from "wow, I'm really grippy today!" to "wow, this sucks."
I'm happy though, Angie La gave me an immediate solution to the problem so I can keep working on what I need to do right now, and more long-term a friend offered to lend me a window AC unit she's not using. If nothing else the window unit should stop me from overheating every time I try to practice! :)
Tamarinda, you might try adjusting your AC unit down if you can. I've read that if AC units are too powerful, they can cool down a room and switch off before they also get a chance to remove much humidity, so the room is cooler, but not substantially less humid. They might not be as effective as central AC, window AC units should decrease the humidity in a room.