Home Repair question - Window leak

[The Wildcard]

Hi there, I got a small water leak in my window. More specifically, it's along the edge where the metal window frame touches the wood indoor frame. The length of the leaking edge is only about 1 ft.

This window is on the 2nd floor of a 2 story building.

Below are some pictures I took from inside my room.
Labeled picture of leak

Zoomed in picture of leak

My guess is that water is coming in from the top of the exterior window cill (shown in the first picture), and is leaking in.

I am thinking I have to climb up there with a ladder and caulk the horizontal edge where the cill meets the exterior wall of my house?

BTW, this problem surfaced recently after having my house painted. Could it be that the painter missed something?

 

[T2T III]

My guess is that water is coming in from the top of the exterior window cill (shown in the first picture), and is leaking in.

-- You are correct in this assumption.

I am thinking I have to climb up there with a ladder and caulk the horizontal edge where the cill meets the exterior wall of my house?

-- Yes, that would be the best plan of attack. When you purchase the caulking, buy 100% silicone caulking made for windows and doors. DON'T buy any cheap painter's caulking. 100% silicone will last a long, long time.

BTW, this problem surfaced recently after having my house painted. Could it be that the painter missed something?

-- Chances are, the painter could have placed his ladder slightly above the window when painting and this could have disrupted the current sealed joint. It also could be a complete coincidence that this leak appeared after your place was painted.