What could be causing the inside of my window to be wet if there's no visible sign of water damage outside the window?

 There could be several reasons why the inside of your window is wet, even if there is no visible sign of water damage outside the window. Some possible causes include:

Condensation: Condensation occurs when warm, humid air comes into contact with a colder surface, such as a window. This can cause water droplets to form on the surface of the window, which can make it appear wet. Condensation is more likely to occur in areas with high humidity, such as bathrooms and kitchens, or during the winter months when windows are closed and the air inside is more humid.

Leaking windows: If the window itself is leaking, it could be causing the inside of the window to be wet. This could be due to a crack or gap in the window frame, a faulty seal, or other issues.

Water infiltration: If the window is not properly sealed or there are gaps around the frame, it is possible that water could be infiltrating the window from the outside. This could be caused by rainwater, melting snow, or other sources of moisture.

If the inside of your window is wet and you cannot identify the cause, it is a good idea to have a professional inspect the window and determine the source of the problem. They can help to identify the cause of the issue and suggest appropriate repairs or remedies.