Windows in Minnesota are a cold-glass problem for as long as the winter lasts. Frost on the room side of a single pane is not a leak. Fog between panes is a dead seal. A meeting rail that whistles on a north wall is a heat leak that can also be the reason a nearby supply line freezes. Wood under a loose storm stays wet and rots the sill by spring. Say which of those you can see with the lights on.
Wind-driven snow finds the casing before it finds the glass. A replacement that does not meet a thick old wall will leak at that joint on the next blow. Divided lites on a farmhouse or a lakeside cottage may be something you mean to keep. Paint will not stop water already behind the stool. If plaster or drywall under the window bubbles only after storms, call it a leak. If it beads every bitter night, call it condensation.
Tell the call which floor, which wall, and whether a bedroom must still open. A sash painted shut is urgent when someone sleeps there. Cords, locks, and a storm panel can be the whole job if the frame is solid. A whole-house count of every opening wastes the first minute. Hardware can wait. A gap you feel with your hand cannot, because this cold turns a draft into a frozen line on the same wall.
Ask what happens to interior trim and the exterior casing. Village houses and city bungalows often want the wood saved. Newer ramblers may be a straight swap if the flange is sound. Either way the opening has to seal, and Minnesota will find the miss. Screens and mild-weather complaints can wait until the heating equipment is not fighting the hole.
Lead with draft, frost, fog, rot, or a stuck sash. Name the north wall if that is the one. Say if a pipe shares that opening. Call the number on this page.