While waking up to frosted windows in the winter can invoke childhood winter memories, frost can actually cause damage to your home. With newer home construction, and the installment of double-paned window technology, window frost is not as common as it used to be. However, it still occurs, and frequently, in older homes.

It may look pretty from the outside, but once the frost melts, it transfers moisture to whatever is next to it. If it is a wooden window, the frost can discolor varnish and crack paint, and it can even damage the wood. Frost can also melt off single-paned windows, seeping into walls all over the house. If moisture is not handled quickly and efficiently, mold can begin to grow and take over.

Frost forms on windows when they are exposed to cold air from the outside, and moist air on the inside. The moisture from the air, or water vapor, is drawn to the window pane. Once the outside temperature lowers past dew point, the water vapor solidifies into liquid, which then freezes into ice crystals on the window.


First, weatherize your windows. Make sure to install either newer double-paned windows or storm windows. Double check that they are installed properly, and fill any gaps in the seals with caulk.

Also, run a dehumidifier. This keeps the air inside your home drier, and frost will be less likely to form in the first place. Keep your house sufficiently warm, especially at night. It may even be worth putting a space heater in certain rooms that are particularly prone to collecting frost. This will also help prevent frost from forming in the first place.