Why Is My Window Leaking Only During Wind?

Wind changes the way rain hits your home. Instead of falling straight down, raindrops are driven horizontally against the window surface. The pressure of the wind can push water into tiny openings that would normally stay dry during a calm rain.

A window is not a solid block; it has multiple joints and seams. The sash, the frame, the sill, and the glass all meet at points where water can sneak in. Wind increases the water's energy, making it more likely to find and exploit any weakness in those connections.

• Cracked or missing caulk around the exterior frame
• Worn or compressed weatherstripping between the sash and frame
• Poorly sealed joints at the corners of the window frame
• A sill that slopes inward instead of outward, trapping water
• Gaps between the window frame and the wall sheathing
• Damaged or missing drip cap above the window

Weatherstripping sits between the moving sash and the stationary frame. It is designed to block air and water when the window is closed. If it is flattened, torn, or missing, wind can drive water right past it.

Open the window and examine the strip along the edges. Press on it to see if it springs back. If it stays compressed or crumbles, replace it with new weatherstripping that matches the original size and type. This often solves a wind-only leak.

If the sealant and weatherstripping look fine, the problem may be in how the window was installed. A window that is not properly flashed or shimmed can have hidden gaps behind the exterior trim. Water can enter at the top or sides and run down inside the wall before appearing at the interior sill.

For a window that leaks only in wind despite good seals, a professional inspection can help. A water damage inspection service can use moisture meters to trace the path of water entry without tearing into walls. If the window itself is the source, window replacement may be the lasting fix.