Water beads on the glass and runs down
The pane looks wet first, then water collects on the sill or stool, especially in the morning or during very cold weather.
Start here: Start with condensation checks and indoor humidity reduction.
Windows leaking
Window Drips After Snow Melt
Direct answer: If a window drips only during thawing weather, the first job is to tell indoor condensation from outside meltwater. Most homeowners either have warm indoor air condensing on a cold window, or snow melt getting into the top or sides of the window opening and showing up at the frame or stool.
Most likely: The most likely causes are heavy condensation on cold glass, a window sash that is not sealing tightly, blocked window weep holes, or exterior flashing and trim details above the window letting meltwater in.
Look at exactly where the water forms and when it happens. Water beading on the glass points one way. Water appearing from the head trim, side jamb, or wall joint points another. Reality check: snow melt can expose a weak window detail that never shows up in a light rain.
Don’t start with: Do not start by smearing caulk around the inside trim. That usually hides the path, traps water, and makes the real repair harder.
If the glass fogs or beads first,treat condensation as the lead suspect before assuming the window is leaking.
If water shows up at the top trim or drywall seam,suspect meltwater getting into the opening above the window, not the sash itself.
Last reviewed: 2026-04-05
What kind of dripping are you seeing?
Water appears from the top trim or drywall above the window
The glass may be dry, but a drip forms at the head casing, upper corners, or paint joint above the window during thawing.
Start here: Start with an exterior-entry check and look for meltwater getting in above the opening.
Water shows at the bottom track or lower sash area
The drip is concentrated in the lower frame, track, or stool, and may happen when snow on the exterior sill starts melting.
Start here: Start with sash seal and weep-path checks.
Only one window does it
A single window or one side of the house drips while others stay dry under the same weather.
Start here: Focus on that opening's seal, trim, and exterior water path rather than whole-house humidity alone.
Most likely causes
1. Indoor condensation on cold glass and frame
This is the most common winter lookalike. The glass gets wet first, then the water runs down and makes the stool or trim look like it is leaking.
Quick check: Wipe the glass dry. If new beads form across the pane while the room is occupied or humid, you are likely seeing condensation.
2. Window sash not sealing tightly
A loose latch, flattened weatherstripping, or a sash that is slightly out of square can let wind-driven meltwater or cold air reach the interior edge.
Quick check: Lock the window and press gently around the sash. If one corner moves or you feel a cold draft, the sash seal is suspect.
3. Blocked window weep holes or drainage path
Many windows are built to shed a small amount of water back outside. If the lower drainage path is clogged, water can back up into the interior track or stool area.
Quick check: Inspect the exterior bottom frame for small weep openings clogged with dirt, paint, or debris.
4. Exterior flashing or trim detail above the window is letting in snow melt
If water shows up at the head trim, upper corners, or wall joint during thawing, the source is often above the visible drip point.
Quick check: Look for missing caulk at the top trim joint, open siding gaps, ice buildup above the window, or staining above the casing.
Step-by-step fix
Step 1: Figure out whether it is condensation or a true leak
This separates the most common harmless-looking moisture pattern from a real water-entry problem before you start sealing things blindly.
- Dry the glass, frame, and stool completely with a towel.
- Watch where moisture returns first during the next thaw or the next few hours indoors.
- If the pane hazes, beads, or gets wet before the trim does, treat it as condensation first.
- If the glass stays mostly dry but water appears from the head trim, side jamb, or wall seam, treat it as outside water getting in.
- Check nearby clues: heavy bathroom use, humidifier use, cooking steam, or closed blinds can all push a cold window into condensation.
Next move: If you clearly see moisture starting on the glass, you can focus on humidity and airflow instead of tearing into trim. If the source still is not obvious, move to the sash and frame checks before assuming the wall is leaking.
What to conclude: Glass-first moisture usually means condensation. Trim-first or wall-first moisture points to meltwater entering around or above the window opening.
Stop if:
- Drywall is soft, swollen, or crumbling around the window.
- You see active dripping from inside the wall cavity.
- There is visible mold growth or a strong musty smell around the opening.
Step 2: Check the sash seal and latch fit
A window that is not pulling tight against its weatherstripping can leak during snow melt and can also run colder, which makes condensation worse.
- Close and lock the window fully.
- From inside, press lightly on each corner of the sash and along the meeting rail.
- Feel for obvious cold air movement with the back of your hand on a windy day.
- Look for flattened, torn, missing, or hardened window weatherstripping where the sash meets the frame.
- If the latch does not pull the sash snug, inspect for a loose or misaligned window latch or lock keeper.
Next move: If tightening the latch or correcting sash position stops the drip, the repair stays in the window hardware or weatherstripping area. If the sash feels tight and the drip still comes from the lower frame or track, check the drainage path next.
What to conclude: Movement, drafts, or uneven contact usually mean the sash is not sealing well. A tight sash with no drafts pushes suspicion toward drainage or exterior water entry.
Step 3: Inspect the lower frame and weep path
If water is collecting in the lower frame and cannot drain back out, it can show up inside even when the main window seal is still serviceable.
- Go outside and inspect the bottom edge of the window frame for weep openings.
- Clear loose dirt, insect nests, or paint blockage gently with a plastic pick or a soft brush. Do not drill new holes.
- Check whether snow, ice, or debris is damming water against the exterior sill or bottom frame.
- Inside, look for water concentrated in the track or lower corners rather than at the top trim.
- After clearing visible blockage, monitor the next thaw to see whether water still backs up inside.
Next move: If the lower frame stays dry after the weep path is cleared, you likely solved a drainage backup rather than a wall leak. If water still appears from the top or upper corners, the source is probably above the sash and frame drainage area.
Step 4: Look above the drip point, not just at it
Snow melt often travels down from higher up and shows itself at the first opening in trim or drywall. The stain is rarely the true entry point.
- Inspect the exterior area above the window from the ground if you can do it safely.
- Look for open joints in trim, failed caulk where trim meets siding, missing pieces of trim, or gaps where meltwater can run behind the casing.
- Check for ice dams, packed snow, or roof runoff dropping directly onto the head of the window.
- Inside, note whether staining is strongest at the upper corners or above the casing line.
- Common wrong move: caulking the interior edge before you know whether water is coming from above.
Next move: If you find a clear path above the window, you have a strong reason to stop chasing the sash and address the exterior water path. If nothing above looks suspicious and the problem is limited to one loose or drafty sash, return to the window-seal repair path.
Step 5: Make the repair choice that matches what you found
At this point you should know whether you are dealing with indoor moisture, a sash-seal problem, a drainage issue, or a larger exterior-entry problem.
- If the moisture starts on the glass, lower indoor humidity, open blinds, improve room airflow, and keep the stool dry while you monitor.
- If the sash is loose or drafty, replace the damaged window weatherstripping and repair or adjust the window latch or lock keeper if it is not pulling the sash tight.
- If the lower frame was backing up, keep the exterior weep path clear and recheck during the next thaw.
- If water is entering from above the window, stop short of blind caulking and arrange an exterior repair of the trim, siding interface, or flashing detail.
- If trim or drywall is already damaged, dry the area thoroughly before cosmetic patching so you do not trap moisture in the wall.
A good result: If the next thaw passes with a dry frame, dry stool, and no new staining, the repair path was correct.
If not: If the window still drips after humidity control and basic window-side fixes, treat it as an exterior water-entry problem and bring in a window or siding pro to open and repair the surrounding detail.
What to conclude: A repeat-free thaw confirms the source. A recurring drip after basic window fixes usually means the problem is outside the visible sash and trim.
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FAQ
Why does my window drip only when snow melts and not when it rains?
Snow melt often moves more slowly and can sit against trim, siding, or the top of the window longer than rain. It also shows up during very cold weather, when condensation is more likely. That is why thaw-related dripping can be either a real exterior leak or indoor moisture collecting on a cold window.
How can I tell condensation from a leaking window?
Dry everything first. If the glass gets wet or foggy before the trim does, that is usually condensation. If the glass stays mostly dry but water appears at the head trim, upper corners, or wall seam, that points more toward outside water getting into the opening.
Should I caulk around the inside of the window to stop the drip?
Usually no. Interior caulk can hide the path and trap water in the wall or frame. It is better to identify whether the source is indoor condensation, a sash seal problem, blocked drainage, or water entering above the window.
Can blocked weep holes really make water show up inside?
Yes. On many windows, the lower frame is designed to drain small amounts of water back outside. If those weep openings are clogged with dirt, paint, or debris, water can back up into the interior track or lower corners.
When should I call a pro for a window drip after snow melt?
Call for help if water is coming from above the window, drywall is getting soft, the frame or trim is rotted, the leak is on an upper story with unsafe access, or the problem keeps returning after you have ruled out condensation and checked the sash and weep path.