Wet floor in the corner, top floor.

[theogn8219]

After 3 days of rain, i noticed the corner of the top floor by the window is wet. I inspected the surrounding walls, the window, the ceiling, and the ceiling directly below the affected area and all have no sign of water issue. Also climbed up to the attic and look around but did not see any sign of leaking water. What would be the issue? Please help.

Additional info, the gutter is directly above the window and the downpipe is attached on the outside of that same corner.

 

[JohnD]

After 3 days of rain... ...the downpipe is attached on the outside of that same corner.

that'll be it then.

might be the gutter overflowing e.g. if blocked with leaves; might be a joint in the downpipe for the same reason; or a crack; might be the wall is damaged there the downpipe is fixed to it.