The short answer: how to get rid of window condensation fast is to wipe the glass dry, open the trickle vents, and get moist air out of the room. Open a window for five to ten minutes, run the bathroom or kitchen extractor for at least 15 minutes, and wring the cloth into the sink, not back into the room. That clears a streaming window in about ten minutes. Keeping it clear takes one more step: stop the moisture building up again overnight, which is where the routine below comes in.

You wake up, the bedroom window is running with water, the sill is wet, and there is a faint musty smell in the corner. It feels like a window problem. In most UK homes it is an air problem, and the fast fix is about removing water that is already there, then removing the moist air that put it there. New windows will not do either job for you.

This guide is the quick-action companion to our longer prevention guide. If you want the full room by room plan for the whole heating season, read that next. This page answers one question: what do I do right now, this morning, and this week, so the windows are dry tomorrow.

How to get rid of window condensation fast in 10 minutes

Do these in order. Each step takes a minute or two, and together they deal with both the water on the glass and the moist air behind it.

1. Wipe the glass and the sill. Use a dry cloth, a microfibre cloth or a window vacuum, and work from the top of the pane down so dirty water does not run over clean glass. Wring the cloth into the sink. Water left on the sill soaks into the frame and the plaster reveal, and that is where black mould starts. The Energy Saving Trust recommends wiping down windows after showering, and the same logic applies every morning: water you remove with a cloth cannot soak into anything.
2. Open the trickle vents. These are the small slotted vents at the top of modern window frames. The Energy Saving Trust advises making sure trickle vents are always open and clear of obstructions. If yours are painted shut or blocked by a blind or curtain, clear them now. Closing them to stop draughts also traps moisture, which is the opposite of what you want on a wet morning.
3. Open the window wide for five to ten minutes. The Energy Saving Trust suggests opening windows several times throughout the day for at least five minutes, and longer if you can. A short, wide opening changes the air without cooling the walls as much as a window left on the latch all day. In a bedroom, do it first thing. If you can, open a window on the other side of the house too, so air moves right through.
4. Run the extractor fan. If the condensation followed a shower or cooking, run the bathroom or kitchen extractor for at least 15 minutes after you finish. The Energy Saving Trust gives 15 minutes as the minimum overrun for both showers and cooking. If you have no fan, leave the window open for at least 15 minutes instead. Close the kitchen or bathroom door while the fan runs so steam does not drift into colder bedrooms, where it will condense on the next cold surface it finds.
5. Move wet laundry out of the room. A rack of wet clothes drying on a radiator in a bedroom sends moisture straight to the coldest window in that room overnight. Move it to one closed room, ideally the bathroom, with the extractor running or a window open. If you must dry indoors, that one-room rule is the single change that makes the biggest difference to morning windows.
6. Check the room temperature. A room that went cold overnight gives you the worst combination: warm, moist air in the evening meeting glass that cooled rapidly after the heating went off. You do not need to blast the heating. A steady background temperature keeps surfaces warmer and shrinks the gap that causes water to drop out of the air. Our thermostat guide explains the setpoints that work for most homes.

That is the whole ten-minute fix. The window should be dry, the air should feel fresher, and you have removed the water before it could soak into the frame. If the glass mists up again within the hour, the room is still too humid, and the morning routine below is what closes the gap.

What to do this morning: the 30-minute routine

The ten-minute fix clears the symptom. This routine, done once in the morning, stops the same window streaming again by lunchtime.

Ventilate the bedroom first. Open the bedroom window for five to ten minutes when you get up, wipe the glass and sill, and leave the trickle vents open. Two people breathing in a closed room for eight hours steadily raise humidity while the window cools, which is why bedrooms are hit hardest at dawn. Morning ventilation is the cheapest cure there is.

Clear the bathroom properly. Run the extractor during every shower and for at least 15 minutes afterwards, keep the door closed while it runs, and wipe the shower screen and tiles with a squeegee. Check the fan actually extracts: hold a piece of tissue near the grille and see whether it is drawn towards it. A fan clogged with dust, or venting into a loft rather than outside, will not clear steam however long you run it.

Contain the kitchen. Use the cooker hood every time you cook, not only for frying. Keep lids on pans, which the Energy Saving Trust lists as a basic prevention step, and close the kitchen door while you cook if steam is spreading. Let the fan overrun for at least 15 minutes. If your tumble dryer is not a condenser model, it should vent outside: a dryer venting into the house can undo a whole day of good ventilation in one cycle.

Check the hygrometer. A small digital hygrometer costs very little and shows relative humidity and temperature at a glance. UK guidance generally treats 40 to 60 percent relative humidity as a comfortable band for occupied rooms. If your bedroom still reads above 60 percent an hour after a shower, your extractor needs longer, a window needs opening, or a door was left open so steam spread through the house. Use the reading to test your routine rather than guessing.

Open curtains and blinds during daylight. Daylight warms the glass slightly and lets moisture vent through trickle vents or an open window. Heavy curtains drawn tight against a cold window all day trap a pocket of cold, still air behind them, which is exactly where condensation forms. Leave a gap at the top, or draw them back during the day.

What to do this week so it stops coming back

Fast fixes clear water. These three changes, done once this week, reduce how much moisture your home makes and how much of it reaches the glass.

Fix the laundry habit. Drying clothes outside is best when the weather allows. When you have to dry indoors, use one room, close the door, and ventilate that room or run a dehumidifier in it. The Energy Saving Trust suggests considering a dehumidifier for dealing with excessive moisture or to help with drying washing inside. Used well, in a closed room where laundry is drying, it pulls moisture from the air faster than a window alone on a wet day. Used badly, left in a hallway with doors open to the whole house, it will run all day and make little difference. It removes water from air, it does not bring fresh air in, and it does not fix a leaking gutter or a failed window unit.

Stop draught-proofing the wrong rooms. Sealing gaps is good for heat loss, but the Energy Saving Trust warns against fitting new draught proofing in a room that does not have enough ventilation or where there is already a condensation problem. Sealing a wet room tighter makes it wetter. Fix ventilation first, then seal. If you are getting a professional to fit insulation, draught proofing or new windows, ask what measures they are including to maintain good ventilation.

Warm the cold spots. Condensation gathers on the coldest surface it can find. A single glazed window in an otherwise insulated room, an uninsulated section at the top of a wall, or a bedroom left unheated for weeks will attract water because that surface is colder than everything around it. Insulation reduces condensation risk when it is suitable, the right type and properly installed, because it keeps surfaces warmer. The practical middle ground is a consistent, moderate background temperature in occupied rooms, heating that does not swing wildly between hot and cold, and attention to the coldest room in the house. If one bedroom is always unheated and always wet, warming that room a little and ventilating it each morning will usually help more than turning the main living room up by several degrees.

Why do windows get condensation?

Condensation forms when moist air touches a surface colder than the air itself. The Energy Saving Trust describes it in exactly those terms: moisture in the air becomes droplets of water when it hits a cold surface, such as a window. In summer your glass is relatively warm and your windows are open more often, so moisture escapes or never settles. In November three things change at once. Outside temperatures fall, so the inner pane gets colder, especially overnight. You close windows for longer to keep heat in, so ventilation drops. And you start drying more laundry indoors, running hotter showers, and cooking with lids off pans in a sealed kitchen.

The scale of moisture in an ordinary home surprises most people. The Energy Saving Trust notes that a typical household can produce up to 100 litres of moisture a week from cooking, showering, boiling kettles and breathing. If that moisture is not removed through ventilation, it stays in the air or builds up on surfaces. By morning the glass is below the dew point of the room air, and water runs down the pane.

Condensation on the outside of a window on a cold, still morning is not a fault. It usually means the window is insulating well, so the outer pane stays cold. Condensation between the panes of a double glazed unit is different again: it suggests the sealed unit has failed and air has got inside. That needs a glazier, not a dehumidifier. Condensation on the room side of the glass, the type you can wipe off with your hand, is the type this guide deals with.

What not to do when windows are streaming

Most bad condensation advice fails in the same way: it treats the water and ignores the air.

Do not close the trickle vents. It feels logical to shut out cold air, but vents are the background ventilation that removes moisture all day without opening a window wide. Closing them traps the moisture that is already in the room, and the next morning is worse.

Do not just wipe and walk away. Wiping is the first step, not the whole fix. If you wipe the glass every morning but never open a vent or run a fan, the water comes back each night, and it soaks into the frame and plaster in the meantime. Wiping plus ventilation is the fix. Wiping alone is mopping a leak.

Do not paint over mould. Mould grows where moisture sits for long periods on a surface that feeds it: paint, wallpaper paste, grout, silicone, timber and dust on cold plaster. Painting over active mould with ordinary paint will not keep it away, and dry brushing it spreads spores into the air. The Energy Saving Trust advises using an antifungal cleaning product or a product designed to kill mould, using a disposable cloth and throwing it away after use, wearing gloves and a mask and any other protection the product label recommends, only wiping mould when it is wet, and keeping the room ventilated while you clean with doors to other rooms closed.

Do not turn the heating off in the wettest room. A home that is not heated properly can contribute to damp, and rooms where the heating is turned off or kept very low in colder months are prone to problems. At the same time, leaving heating on all the time just to avoid damp is not a sensible or affordable solution. The middle ground is steady background heat in occupied rooms, not short fierce blasts followed by a cold house.

Do not use unflued gas heaters. Portable bottled gas and paraffin heaters produce a large amount of water vapour as well as heat, so they add to the very problem you are trying to clear. Local authority guidance across the UK consistently advises against them in homes with condensation.

When fast fixes are not enough

Sometimes streaming windows are a symptom of a bigger problem, and no amount of wiping will fix it. Watch for these signs.

Condensation between the panes. If water is inside a double glazed unit and you cannot wipe it away, the edge seal has failed. The unit now insulates less well. A glazier can usually replace just the glazed unit rather than the whole window.

A tidemark along the bottom of a wall. That is rising damp, where groundwater moves up through masonry, often because a damp proof course has failed. It needs a building fix, not a ventilation routine.

A damp patch that grows after rain. That is penetrating damp: rainwater getting in through a leaking roof, blocked guttering, cracked render or poorly sealed windows. Clear the gutters and fix the leak first.

Mould that keeps returning in the same place. If mould covers a large area, keeps returning despite good ventilation, or is linked to a leak or rising damp, get professional advice. In a rented home, report persistent damp and mould to your landlord rather than only cleaning it repeatedly. Government guidance on damp and mould is clear that the underlying causes, including building deficiencies, inadequate ventilation and condensation, need to be identified and tackled, and that simply removing surface mould will not prevent it from reappearing. Damp and mould primarily affect the airways and lungs, and can cause serious illness in the most severe cases, so a problem that keeps coming back deserves a proper diagnosis, not another cloth.

Water on walls and ceilings, not just glass. If moisture is building up somewhere other than on the window, you might not notice until wallpaper starts to peel or black mould starts growing. That is a whole-house moisture problem: check extractor fans, look for leaks under baths and sinks, and check for gaps in insulation at the top of walls or around loft hatches.

How to get rid of window condensation fast: frequently asked questions

How do I get rid of condensation on windows fast? How to get rid of window condensation fast is a three-part job: wipe the glass and sill dry, open the trickle vents and a window for five to ten minutes, and run the extractor fan for at least 15 minutes after showering or cooking. That clears a streaming window in about ten minutes. To stop it returning, dry laundry in one closed, ventilated room and keep a steady background temperature.

Should I wipe condensation off my windows every morning? Yes. Water left on a sill each morning soaks into the frame and the plaster reveal, and black mould follows in the corners where the air is stillest. Wipe with a dry cloth or a window vacuum and wring the water into the sink. But wiping alone is not enough: pair it with ventilation, or the water returns the next night.

Does opening a window get rid of condensation? Yes, and quickly. A short, wide opening changes the moist air for drier outside air without cooling the walls as much as a window left open all day. The Energy Saving Trust suggests opening windows several times throughout the day for at least five minutes. In a bedroom, five to ten minutes first thing is the most useful single habit.

Why is condensation worse in the morning? Bedrooms combine overnight breathing in a closed room with the coldest glass in the house before dawn. Two people breathing for eight hours steadily raise humidity while the window cools, so by morning the glass is below the dew point of the room air and water runs down the pane. Morning ventilation, trickle vents and wiping the sill usually improve bedrooms fastest.

Can window condensation cause mould? Yes. Mould grows where moisture sits for long periods on a surface that feeds it, and the Energy Saving Trust is clear that mould can affect health, causing symptoms such as nasal stuffiness, wheezing, and eye or skin irritation. Children, older people and people with skin or respiratory conditions are particularly at risk. Daily drying is prevention: water removed with a cloth cannot soak into grout, silicone or plaster.

How do I dry a wet window sill? Wipe it with a dry cloth first thing, then ventilate the room so the frame can dry out during the day. If the sill is already stained or soft, the water has been sitting there for a while, which means the daily wipe has been missed or the room needs more ventilation. Do not paint over a damp sill: dry it, clean any mould with an antifungal product while wearing gloves and a mask, and fix the moisture source before redecorating.

Related reading

• How to stop condensation on windows: the room by room guide for the whole heating season
• What temperature should you set your thermostat in winter?
• How to stop draughts in windows and doors without trapping moisture
• Should you bleed your radiators before winter?
• Secondary glazing vs double glazing: the cheaper way to cut draughts and heat loss

Sources

• Energy Saving Trust: How to get rid of damp (up to 100 litres of moisture a week per household; trickle vents always open; open windows for at least five minutes; extractor fans for at least 15 minutes after showers and cooking; wipe windows; dehumidifier for excessive moisture; mould cleaning guidance)
• GOV.UK: Understanding and addressing the health risks of damp and mould in the home (damp and mould primarily affect the airways and lungs; causes include building deficiencies, inadequate ventilation and condensation; removing surface mould will not prevent it reappearing)
• Buckinghamshire Council: Keep your home free from damp and mould (wipe windows and sills every morning with a dry cloth; dry clothes outside where possible; keep heating steady in winter)