I’ve heard that yurts aren’t necessarily the best choice for humid locations, but I think you can definitely still make it work. I would definitely get an insulation kit to go with it. I know that sounds silly when heat and humidity are the issue, but it will help keep the yurt somewhat cooler inside.
I would build a wooden platform to place the yurt on, and have it raised off the ground at least a foot, maybe more if your area is prone to flooding. I’d also suggest doing concrete footings for the vertical supports. It’ll make the whole thing more stable. Having the yurt off of the ground will eliminate water from seeping into the yurt.
I would also add at least three windows for ventilation so that when it’s hot you have the windows and door open to create a cross breeze. A screen door is optional, but if you’re going to need to keep the door open for airflow I’d highly recommend it.
Adding Tyvek (or similar product) was mentioned in an earlier comment. I think that it’s a great idea. It’ll give you a moisture barrier between the covering of the yurt and the yurt frame, which if you’re using wood for the frame would be needed to keep moisture off of the wood.
A wood stove will give you a couple of advantages. It’ll heat the space, give you something to cook on, and keep the inside dry as well. If you run electricity to the yurt you could add a dehumidifier as well. That would probably be a good investment for humid areas and they don’t cost too much.
You may want to research fabrics for covering the yurt, I’m not sure canvas would help or hinder. It does keep rain out when it’s raining on me, I just don’t know about humidity. I bought mine through
https://www.simpleterra.com/yurt-kits/ and I’d check with them, they’d probably know more.
