Attic with lots of damp spots on the insulation

[Scott Krueger]

I am in the process of purchasing a property in Iowa. It is winter here and the house inspector did not enter the attic due to personal items blocking access at the time of the inspection. I personally went into the attic today and I saw lots of damp spots on the insulation above the ceiling. The roof tiles don't look the newest, but they I've seen plenty worse. I figure these spots could be either from condensation or seepage. They were more common toward the outer edges and lower parts of the roof.

Anyone have any insight on what this may be the cause and what this might mean in terms of the roof needing to be replaced?

Thank you,

Scott