Ghosting on vinyl siding

[labstein (Les Abstein, CMI)]

This is a good thread on this:

Mystery marks on vinyl siding

I found these stains on vinyl siding and don’t know what may be causing it It appears to be a repeating pattern in that it occurs about every 16 inches. But I don’t know how the stud spacing would make such marks. This is the south facing wall. It has not rained recently It was cold but sunny , 9:30 am 1994 construction. Have you seen anything like this before? Any thoughts on the cause? [image] [image] [image]