I have condensation appearing on the ceiling of the top floor of my house on the north side, We are moving into winter and its starting to cool off, it appears to be all along the outside edge of the ceiling near the area where the ridge vent would be and especially in front of the window. In the attic there are Styrofoam forms that hug the plywood to allow air flow and the insulation is batting. I'm guessing it has to do with the cool temperatures outside and warm temperature inside and how the attic is insulated but that's just a guess? Any help would be greatly appreciated.

Thanks