Windows in Kentucky swell in river humidity and then gap when a dry cold finally shows up. Wood sashes stick shut all summer and rattle in January. Failed seals fog and stay milky because the air never really dries them out. Wind-driven rain finds the meeting rail on the storm side. A cold room beside working heat is often the opening. A sash that will not move is not a quirk to plane away without looking at the sill.
Older town houses still carry wood double-hung units, sometimes painted shut for years. Newer subdivision vinyl fogs as a set when that seal dies. An insert in a soft, swollen sill leaves the rot in the wall. Full-frame work is the right mess when the stool is mush. Say what the wood feels like. Keep chalking paint contained, especially in older houses where the dust should not travel the room.
Shade and splash matter more here than a long freeze. A window under a tree or over a low porch stays wet and grows soft trim. Ask how the sill is flashed and what fills the gap so humid air does not sit in the wall. Interior trim and an outside cap finish the job. West walls take the storms. North walls stay damp. Forcing a painted sash cracks the rail, and some hardware can be repaired when the frame is still sound.
Count the openings that stick, fog, or rot, not every window on the house. One rotten bath window and sound fronts are common. Fog in a builder unit may mean others of that age are close, yet report what you see. Say the town, the floor, and whether the complaint is swell, fog, or a draft on the few hard nights. Hill houses and valley houses do not take the same rain.
Do not sand old paint through the room. Say how many openings hurt and whether the frames are soft from moisture rather than from a deep freeze. Call the number on this page.