I recently purchased a 2 story home built in the mid- to late-1800's. During the colder winter months, the upstairs windows (2nd floor) have been collecting an excess amount of condensation on the inside. They are the single pane original windows. There are storm windows on the outside. We've done some caulking, around the sides and top of storm windows (not the bottom), and around the window trim. Is it possible we've made them too airtight or even that our attic isn't venting properly?

Thanks and any advice helps