This page is the glass. A mark on the plaster belongs on the damp-patch page. Water at a door or an air brick belongs on the surface-water page. A stain that starts on the ceiling belongs on the roof-leak page. If a carbon monoxide alarm is already sounding, leave the house. The alarm page is the test you do before a planned fire.
Read the live forecast again before you treat Saturday as settled. The note below is the Met Office blog published on 8 October 2026. A later warning can change the wind, the showers and how cold the glass gets. The sort of the mist does not change with the forecast: which side of the glass is wet still decides the trade.
What Saturday does to the glass
On 8 October the Met Office published Weekend weather: blustery showers before a quieter Sunday. Saturday is the more unsettled day. Showers move through widely. Northern parts of the UK, and Scotland in particular, are in line for the most frequent and intense ones, with a risk of hail and thunder, and a possible brief sprinkling of snow on the highest ground. The far south and south-east sit more in the lee of the north-westerly flow, so they have a better chance of brighter spells. The wind is brisk. Temperatures sit around average for the time of year, or slightly below in places, and the wind makes it feel colder. Across northern areas in both the wind and the showers, it may feel closer to the high single figures.
Saturday night is the part that matters for the windows. Showers ease as a ridge of high pressure builds. Clearer skies become more widespread. A brisk wind continues through much of the night, and temperatures stay mostly in the high single figures. Sunday morning starts chilly, then the day itself is brighter and drier for many places before wet and windy weather returns from the west later on. Clearer skies let heat leave the pane. The inside face of the glass is then one of the coldest surfaces in a room that was shut against the wind.
Moisture is already in that room. Cooking, showers, drying clothes indoors and people breathing all add water vapour. When that vapour meets a cold surface it becomes droplets. Energy Saving Trust’s damp and condensation advice, last updated 22 May 2026, says moisture in the air forms condensation on a cold surface such as a window, that a cold morning often shows it, and that it is a problem when it does not clear quickly. A bead of water on the bedroom glass at dawn on Sunday can be that ordinary meeting of moist air and a chilled pane. It becomes a maintenance job when the same glass is wet every morning, when black growth appears on the silicone or the reveal, or when the water is somewhere you cannot wipe.
The NHS page Keep warm, keep well says to heat your home to a temperature that is comfortable for you and, if you can, to at least 18°C in rooms you use regularly, such as the living room and bedroom. That matters particularly if you have a health condition. The same page says it is best to keep bedroom windows closed at night. Those two lines sit beside ventilation, they do not cancel it. You air the house in the daytime. You leave the small background vents open. You do not prop the bedroom window open all night and call that a cure, especially where someone in the house is in a group the NHS lists as more affected by cold: people aged 65 and over, babies and children under 5, people with a long-term health condition, pregnant women, and people who cannot afford to heat the rooms they use.
Where the mist is sitting
Look before you wipe. Touch the room side. If it is dry, look at the outside, then look into the gap of a double-glazed unit. Write down the room, which side is wet, and whether the mark appears after a shower or only after rain on the frame. Those three facts are what you say on the phone.
| What you can see | What it usually is | What to do next |
|---|---|---|
| Beads on the room side, worst on a cold morning, clearing once the room warms or you open a window | Condensation from moisture already indoors | Air the room, keep trickle vents open, wipe with a dry cloth |
| A mist or droplets between the two panes, dry to the touch on both the room side and the outside | A failed seal in the double-glazed unit | A glazing repair. Open building and describe the unit |
| Water on the outside of the glass on a cold, clear morning, with a dry room | The outer pane is cold enough to dew. Energy Saving Trust’s windows advice, last updated 20 May 2026, treats outside condensation as a sign the glazing is doing its job | Leave it. It should clear. It does not need a trade |
| Water at the frame or a stained reveal only after rain, including Saturday’s showers | Weather getting in at the junction, or from a gutter above | The gutter page if the trough is spilling, then building |
| Black growth on the seal, the reveal or the wall beside the window, returning after a wipe | Moisture that has been sitting long enough to grow | Stop scrubbing if it spreads or someone is unwell. Report it if you rent |
The same windows page says condensation between the panes means the unit is letting air in, which weakens the glazing, and that the panes can often be replaced rather than the whole window. A dehumidifier in the room cannot reach water trapped inside the unit. Replacing the glass is a glazing job. If the firm wants to change the whole window, the building regulations note is the page that explains when a replacement window needs approval. That note does not book the work.
A card that lists FENSA is showing a qualification field already on the listing. This site does not sell that as a badge, and it does not check the card for you. Ask the person who comes to show whatever certificate covers the job in your nation. England and Wales are where FENSA is the familiar scheme for many replacement windows. Scotland and Northern Ireland use their own building standards. Say which nation you are in when you phone.
What to do before you buy anything
If the water is on the room side and the frame is dry in the rain, start with air and a cloth. Energy Saving Trust’s damp page, last updated 22 May 2026, is the sequence below. It is ordinary housework. It is not a treatment for a failed seal or for rain coming through the frame.
- Confirm the wet face. Room side, outer face, or the gap between panes. Wipe only what you can touch.
- Leave trickle vents open. Energy Saving Trust’s ventilation advice says to keep them open all year, including in colder months. Closing them to stop Saturday’s wind is how Sunday’s glass streams.
- Run the extractor while you cook, shower or bathe, and leave it running for at least 15 minutes afterwards. If the room has no fan, open a window for that same stretch, including the 15 minutes after you finish.
- Open windows for at least five minutes, several times during the day. Where you can, open more than one side of the house so air can cross. Do this in daylight. At night, follow the NHS line and keep bedroom windows closed.
- Dry washing where the moisture can leave. Outside in a dry gap if Saturday gives you one. Indoors, use the room with the fan or an open window. A shut bedroom with a radiator and a clothes horse loads the glass by morning.
- Hold the rooms you actually use at a temperature that is comfortable. If you can, that is at least 18°C where the NHS note applies. A spare room left cold, with the door open onto a steamy landing, will mist even when the living room feels fine.
- After you have aired, wipe remaining beads with a dry cloth and dry the sill. Wiping a shut room only moves the water from the pane to the timber.
Leave trickle vents, air bricks and extractor grilles open. Energy Saving Trust’s draught-proofing advice says those openings are there so the room can breathe. Tape over them for one cold weekend and the moisture stays indoors.
A bathroom fan that is silent, that does not spin, or whose grille has been painted shut, has stopped doing the job in the list above. Tell the landlord if you rent. If you are booking the repair yourself, open electrical and say which room and that the fan does not run. Do not take the cover off. A new circuit, if someone proposes one, can fall under Part P in England. The Part P note explains notification. A listing that shows NICEIC or NAPIT is showing a field that is present. It is not a badge this site sells.
A dehumidifier can pull water out of a room that keeps misting after you have aired it. It does not repair a seal, a gutter or a fan. Empty it, and keep it off a trailing lead across a wet bathroom floor. If the only way the house stays clear is a machine running all day, the fan, the vents or the glazing still need a look.
When a wipe is no longer enough
Light mist that is gone by lunchtime, on a dry frame, can stay on this list for a few ordinary days. Black spots that return on the same reveal, a musty smell, or mould that has moved onto the wall beside the window are past a Sunday cloth. Do not set a child, someone who is pregnant, or someone who is already unwell to scrub it. The NHS cold-weather groups above are a reason to report sooner, because damp and cold land harder on those households. Say who lives in the home when you report it. A photograph of the reveal, the date, and whether you have been airing the room are enough to start.
In England, social housing already has a clock for this. GOV.UK’s tenant guidance on Awaab’s Law says it applies to England. For most council and housing association tenancies, a significant damp and mould hazard must be investigated within 10 working days of the landlord becoming aware of it, and the home must be made safe within 5 working days of that investigation finishing. The landlord must give a written summary within 3 working days after the investigation, unless the work has already been started and completed within those 3 working days. Further work should be under way within 5 working days of the investigation, and all of that remaining work must physically begin within 12 weeks at the latest. An emergency hazard — the guidance includes very serious damp or mould, alongside things such as a gas leak or a major leak — must be investigated and made safe within 24 hours. Supported housing and temporary accommodation may be a licence rather than a social tenancy. The same page says to check the agreement, and to report the hazard either way.
That page does not hand the same deadlines to a private landlord. If you rent from a private landlord, write to them with the room, the dates and the photos, and keep a copy. Scotland, Wales and Northern Ireland are outside that England guidance. Use the repair route your own nation and your tenancy already give you. This site does not send the report and does not decide whether a patch is “significant” or an emergency. You describe what you can see and who sleeps in the room. The landlord’s category is theirs to make.
A later phase of the same England rules starts on 30 November 2026. The Phase 2 guidance for social landlords says that from that date the significant-hazard list also covers excess cold, excess heat, falls, structural collapse, fire, electrical hazards and domestic hygiene, alongside damp and mould, which has been in force since 27 October 2025. You do not wait until 30 November to report mould that is already on the glass. The damp and mould clocks above are already running for the social tenancies they cover.
Owner-occupiers do not have that landlord clock. The same sort still applies: air and wipe room-side mist, book glazing for a failed unit, and book a builder if rain is coming in at the frame.
Who to call, and what to say
Stop the homeowner sequence if any of these are true. They are calls, or a report, and another wipe will not finish them.
- The mist sits between the panes and both faces you can touch are dry. Ask a glazing firm, via the building list, whether they replace the sealed unit or the whole window, how many openings you have described, and whether the figure is plus VAT.
- Rainwater is entering at the frame or under a spilling gutter. Stay off the ladder while Saturday is windy. Use the gutter page for what you can see from the ground, then a builder if the junction itself is wet.
- The extractor does not run. An electrician for that fan, after you have told a landlord if the tenancy puts the repair on them.
- You smell gas, or the carbon monoxide alarm sounds. Leave, avoid switches, and call the Gas Emergency Service on 0800 111 999. The alarm page is for a test you planned, not for an alarm that is already going.
- A gas fire or boiler shows a lazy yellow flame, sooty marks, or mist in that room that never clears. Stop using the appliance. Do not open the case. Gas work done as a business belongs with a Gas Safe engineer. The Gas Safe note says when that register applies.
On a glazing call, say the room, whether you can wipe the mist, the frame material if you know it, and how long the unit has looked cloudy. On an electrical call, say the fan is dead and whether a breaker opened when you tried it. On a landlord report, say who lives there, especially anyone aged 65 or over, under 5, pregnant, or with a breathing or other long-term condition. Ask when they will visit. For an England social tenancy, ask them to treat it under the Awaab’s Law clocks if the mould is more than a one-off morning mist.
City lists are the same idea with a place attached, for example building in Manchester or electrical in Glasgow. You use the number on the card. The contact-details page only shows how that call works. Nobody here forwards the job, and a guide is not a quote. Pounds for a repair live on the cost notes. A scheme such as the Boiler Upgrade Scheme lives on the grant notes. Window mist does not, by itself, make you eligible for either.
Questions that decide the next step
Is morning mist on the room side of the glass a leak?
Usually it is moisture already in the room, landing on cold glass. Energy Saving Trust says condensation on a cold morning is common, and that it is a problem when it does not clear. Water that appears only when rain hits the frame is weather at the junction. A stain that grows on the ceiling is the roof-leak page.
What if I cannot wipe the mist from either side?
Mist trapped between the panes of a sealed unit is a failed seal. Energy Saving Trust says air is getting into the unit, and the panes can often be replaced. A dehumidifier will not clear water you cannot reach. Describe it as a sealed-unit repair when you phone.
Does Awaab’s Law set a deadline for every UK tenancy?
The GOV.UK tenant guidance applies to England and to most council and housing association tenancies. A private tenancy is not given those social-housing clocks on that page. Scotland, Wales and Northern Ireland use their own rules. Report what you can see either way: the room, the dates, and a photo. This page does not file it.
Need a number for the fan or the glass?
Open the list, pick the city, and contact the business yourself.