We had a very wet summer this year and noticed a lot of my wood didnt dry down very well either. Most of what i cut split and stacked last winter was still pretty green this fall. Oak can take 2 years, but i usually dont have problems getting ash and elm ready in a year. Even the pine and popple i cut which should be tinder dry by now was close to 30%. But it seemed to rain every other day this summer and it continued well into fall.
Also, is your wood stacked in rows? Sunlight and air movement helps a lot. I've noticed if I just leave it in a big pile the outer stuff dries up nice, but the wood in the middle takes a long time to dry down.