I think most of the problems I had when I was in Utah were because of the low moisture. Rapid drying is going to make any moisture issues worse. I would guess the pine ply coming off a stack is not fully dry. But when you take it home, the drying starts immediately.

When I moved east, I remembered the high humidity days in Utah when it hit 50%. Of course, those were always hot days and that means the swamp cooler is ineffective. Here in Pennsylvania, that's a low humidity day.