We have an 11 year old bungalow and this problem only occurs on the middle section of a bay window. We think that frost happens inside the insulation somewhere and when the temperature outside is mild the frost melts and water drips under the interior window trim and drips onto the slats of the blinds and pools on the window sill. We never have any water leakage when it rains.
We took out a large chunck of foam insulation in anticipation of mild weather and this morning the spot we had cleared was dripping. What do we do now?