I live in Florida and its only humid during the summer. The winter months can be quite dry.
Having said that, I have gotten deliveries where the boxes were wet, but thats only because the driver was to lazy to open the screen door and throw the box inside. Instead leaving it out in the open.
That happened to me once with an Amazon shipment and the three books were completely ruined. Amazon made good on it though.
SE Asia is always humid. I lived on Okinawa for a year. Its always damp and nothing seems to really get dry.