How often should windows be cleaned? Every 4 to 8 weeks is the honest answer for most UK homes, and it’s the schedule most professional rounds run on.
That range isn’t arbitrary. It’s the point where grime comes off in one pass and never gets a chance to bond to the glass. We run a window cleaning round in Dorset, and the difference between a six-weekly house and a once-a-year house is measured in scrubbing time.
The Short Answer, By Situation
Different homes sit at different points in the range. This is where yours probably lands:
| Your situation | Recommended frequency |
|---|---|
| Most UK homes | Every 4–8 weeks |
| Coastal homes (salt spray) | Every 4 weeks |
| Busy road (traffic film) | Every 4 weeks |
| Under trees (sap, birds, pollen) | Every 4–6 weeks |
| Interior glass | 2–4 times a year |
The bare minimum that still protects the glass is twice a year.
What Actually Dirties Your Windows
Rain gets blamed, but rain is mostly innocent. What it does is carry everything else onto the glass and leave it there as it dries.
The real culprits depend on where you live. Traffic film near main roads, salt haze near the sea, pollen and sap under trees, and everywhere gets airborne dust, spider webbing and bird mess.
Coastal glass deserves special mention. Salt is abrasive and hygroscopic, meaning it keeps pulling moisture onto the pane, which is why homes near the sea in places like Weymouth need the 4-weekly end of the range.
Why Professional Rounds Run on a Fixed Interval
Most professional rounds in the UK settle on a fixed interval somewhere in the 4-to-8-week band, and there’s good logic behind it. One consistent schedule means efficient local rounds, dependable visit dates, and glass that never gets the chance to reach the visibly dirty stage.
Our own round runs every six weeks, for every residential customer. It sits right in the middle of the ideal range: frequent enough to stay ahead of grime in almost any UK setting, spaced enough to keep the service efficient and reliable.
The full detail of how the round works is on our regular window cleaning page.
Why Winter Cleaning Matters More, Not Less
Every autumn, some customers ask about pausing until spring. It’s the wrong instinct, and we tell them so.
Grime builds fastest between November and February: more rain splash, more road spray, more time with the heating condensing moisture on cold glass. To add to the impact, the low winter sun sits at exactly the angle that shows every streak and spot.
Pure water cleaning is unaffected by cold or drizzle, so there’s no technical reason to stop. The houses that pause are the ones that need a heavy first-clean again in March.
Signs You’ve Left It Too Long
Glass tells you when a clean is overdue. Look for these:
- A grey film that doesn’t shift with rain
- White mineral spots that stay after the glass dries
- Green algae creeping in from the frame edges
- Dirt packed into the sill channels
- Frames that look grey rather than white
The last two matter beyond looks. Packed sills hold water against the seals, and that’s how sealed units start to fail.
Set It Once, Then Stop Thinking About It
The real answer to “how often” is: pick a schedule once and automate it. Homes on a round never sit at either extreme, because the schedule does the remembering.
If you’re in Dorset, joining our six-week round takes one short enquiry form, and in many cases we can quote without visiting. Everywhere else, the 4-to-8-week rule and the table above will steer you right.
Frequently Asked Questions
What month is best to clean windows?
There's no magic month, because grime builds all year. If you only clean occasionally, spring and autumn cleans catch the pollen season and the winter run-up. A regular round makes the question irrelevant.
Should windows be cleaned in winter?
Yes, and arguably winter matters most. Low sun shows every streak, daylight is scarce, and rain splash and traffic film build fastest between November and February. Pure water cleaning works in cold weather, and rounds run all year.
How often should the inside of windows be cleaned?
Two to four times a year is enough for most rooms, more in kitchens where cooking film builds. Exterior glass weathers far faster than interior glass ever will.
How often does the average person clean their windows?
Honestly? Less often than any guide recommends. Ask a UK forum and answers run from monthly to never. Homes on a professional round average every 4 to 8 weeks, which is where glass stays consistently clear.
What happens if you never clean your windows?
Grime bonds to the glass and can permanently etch it, algae stains the frames, and dirt packed into sills holds water against the seals. Replacement is the expensive version of a £20 clean.