The rate of drying is determined by relative humidity at the surface. And beyond that, further inside, the moisture content looks something like a bell curve, with the outside low and higher toward the center (hence re-splitting when measuring). Rain or snow, or high humidity like shade or an enclosed area, would slow or reverse the process. It just depends on how long and how much.Does rain (wet wood surface), reduce the escape across cell membranes?
Here I don't cover. So some of it does get fairly saturated after a rain storm or heavy snows. Right now the stacks outside have a foot or more of snow on them, so they're getting saturated quite a bit. At least for the top couple layers are. The top couple layers are in direct sun though, so get the brunt of any heat when the sun is out. And we do get a fairly severe drought every year around July and August. So whatever effect rain and snow does have, it seems to get baked back out by late summer. Late summer we bring some inside to keep it dry.