It is probably missing some caulk or sealant on the exterior. The exterior is the first line of defense.

This would seem to be in a window well. So in addition to the other comments, make sure your well drain is not clogged. I guess first though, verify if you have a drain.

+ 1 to the other comments, you'll want to see what's going on outside. The window frame shouldn't be buried at all and there should be sealant intact on all sides. Have you ever had standing water in the window well? If so, that would need to be addressed in terms of drainage as another poster alluded to. We've had a customer or two over the years contact us about leaking only to find the window well full of water like a fish tank. The window nor the installation is designed to withstand that.

You need proper drainage design both in the well if there is one and exterior grading . You have to plan for heavy snowfalls and cover the openingsif needed, advanced design methods woud incoparate a drain in to your drain tile system if you have one.

thanks all. No issue with drainage in the well and it is covered in winter. bottom of window is much higher than bottom of well and several inches from sides of well. seems to had gotten a lot worse after a high wind and rain event with the rain beating heavily against that side of the house.

Have you seen any signs of termites or dirt duabers? the ”soil” you see may be from Dirt Dauber nests or termite columns that are being ”washed” down to that area from a leak above the window.

The snow finally cleared enough for me to identify where the water was entering - picture here - what is the likely weak point in the window? top or side? the top of the stain is the highest intrusion point from the interior a little over half way down the window. Can’t get down into the well yet but this was a result of pouring water along the top of window from exterior.

Lets see a picture of the outside and above the window. Thanks.