Hang a board or long pole between limbs on 2 different trees, or, put 2 posts of some sort in the ground, and fasten the board or post to them.
Stand the lumber on edge leaning against the pole or board,
Alternate from one side of the pole or board, to the other. This leaves air space. Rain does not matter, for a good while.
Usually, one or 2 guys are sent out to turn the lumber to the other edge, every 2-5 days, to prevent warpage.
If it works in the tropics, with daily rain storms, I see no reason for it to not work up in the Nawth.
