Windows
Exterior window cleaning before winter: timing the last clean of the year in the GTA
The short answer
Book or do the last exterior clean after most leaves have fallen and the gutters have been cleared, and before daytime highs stop reliably clearing freezing. At Toronto Pearson, October averages 25 days with a high above 10 °C and November only 9, while November averages 15 nights at or below 0 °C. For most GTA houses that points to late October or the first half of November, on a dry, calm day.
Exterior window cleaning before winter comes down to picking the date. Do it in early October and the leaves, the gutter work and the first windy rain can undo it before the season ends. Leave it to late November and you are working on wet ladders with water freezing in the tracks. This guide sets the date from the published climate normals for the GTA and from the order the other autumn jobs have to happen in.
When should the last outside window clean of the year happen in the GTA?
For most houses in Oakville, Mississauga, Burlington, Milton and Etobicoke, the useful gap is late October to mid-November: after the bulk of the leaf drop and the gutter clean, and before the run of freezing nights. The exact date is set by your trees and by the forecast, and the climate record shows how fast that gap closes.
Environment and Climate Change Canada publishes 1991–2020 climate normals for Toronto Pearson, the airport station in Mississauga. Your own street will not match the airport reading every night, so treat these as the shape of the season rather than a forecast.
| Month | Average daily high | Average daily low | Days with a high above 10 °C | Days with a low at or below 0 °C | Days with measurable rain |
|---|---|---|---|---|---|
| September | 22.3 °C | 11.6 °C | 29.9 | 0.16 | 10.2 |
| October | 14.6 °C | 5.3 °C | 25.2 | 3.0 | 12.8 |
| November | 7.9 °C | 0.2 °C | 9.2 | 14.6 | 10.4 |
| December | 1.9 °C | -5.0 °C | 1.6 | 25.5 | 7.5 |
Three things in that table decide the plan. October has the most days with measurable rain of any month in the year at this station, so an October clean has the most chances to be spattered again. November keeps an average low of just 0.2 °C, which means roughly every second night is at or below freezing. And the number of genuinely mild days drops from 25 in October to 9 in November and under 2 in December. The same record puts the average first fall frost on October 20.
Why the leaves and the gutters have to come first
Cleaning the gutters puts wet debris on the walls and on the glass directly under the eaves, whether the work is done by hand from a ladder or with a blower. If the windows are washed first, the upper-floor glass and sills get done twice. Leaves do the same thing on a smaller scale: wet leaves stick to glass, sills and frames, and a windy day in the middle of the leaf drop can undo a clean on the side of the house facing the trees.
The municipal leaf programmes are a practical signal for when the drop is being dealt with on your street. The Town of Oakville's 2026 loose leaf collection runs from October 26 to December 4, zone by zone. How often the gutters themselves need clearing under mature trees is covered in how often eavestroughs need cleaning in the GTA.
- Wait until most of the leaves on your own trees and the trees overhanging the roof are down.
- Clear the gutters and check that the downspouts run. This is the job that puts debris onto the glass and sills below.
- Take the screens out, label them and store them. The steps are in taking window screens off before winter.
- Clean the exterior glass, then the frames, sills and tracks.
- Only then unscrew the hose, turn off the outdoor water supply and let the taps drain. You need that water for step four.
The last step matters because it is the one that ends the outdoor season. The City of Toronto's frozen-pipe guidance is direct about it: outdoor faucets are the first to freeze, so hoses come off, the outdoor supply is turned off and the taps are drained. Once that is done, do not turn the supply back on for one more rinse on a cold afternoon.
What the weather decides on the day itself
A good date on the calendar still has to pass four checks on the morning. If any of them fails, move the day rather than working around it.
- Is the glass dry?Autumn mornings leave dew or frost on the outside of the glass. Cleaning over it dilutes the solution and leaves a film as it dries, and frost has to melt and dry off first. Start on the side of the house the sun reaches first, where it dries soonest.
- Will it stay above freezing tonight?Water that runs into sliding tracks, sills and the weep slots at the bottom of the frame does not all evaporate before evening. On a night at or below 0 °C it freezes there, and ice in a track can hold a sliding sash shut. On a borderline day, finish early and wipe the tracks dry.
- Is it windy?Wind dries solution on the glass before it can be wiped off, blows debris back onto clean glass and makes any ladder work harder to control. At Pearson, days with winds of 52 km/h or more average 0.67 in September, 2.2 in October and 2.5 in November.
- Is the ground dry and firm?The Canadian Centre for Occupational Health and Safety says not to use ladders on ice, mud or other slippery surfaces, and to avoid climbing with wet soles. Wet leaves on a lawn or a patio count. If the ladder footing is not firm, the upper floor waits for another day.
Low autumn sun is the fifth thing, and it changes the order rather than the date. When the sun sits low and shines across south- and west-facing glass, it shows every streak and dries the solution fast. Clean those sides while they are in shade and check them afterwards in the sun. If a streak survives, the reasons and the fix are in why windows streak after cleaning.
What has to happen before winter, and what can wait for spring
Dirty exterior glass over winter is a cosmetic problem. The parts of the job that matter before the cold are the ones that hold water against the frame or stop it draining. If the season gets away from you, do those and let the glass wait.
| Part of the job | Before winter? | Why |
|---|---|---|
| Weep slots at the bottom of the frame | Yes | Blocked slots keep water in the frame, where it can freeze |
| Sliding tracks and sills | Yes | Leaves and grit in a track hold moisture against the frame all winter |
| Screens | Yes, out and stored | A screen left in collects wet debris and blocks the outside of the glass |
| Exterior glass | Optional | Worth it for winter light; nothing is harmed if it waits for spring |
| Interior glass | Any time | No weather dependency, so it does not need an autumn slot at all |
Moving the interior glass off the autumn list is the easiest way to make the outdoor day shorter. It can be done on any grey afternoon in December or January, when nothing outside can be done anyway.
Doing it yourself, and when to book it instead
A bungalow or the ground floor of any house is a reasonable afternoon with a bucket, a squeegee and a cloth for the tracks. There is nothing to gain by hiring that out if you have the time and a dry day. Second-floor glass is where the answer changes, and the reach, ladder and stopping-point questions are laid out in exterior window cleaning on a two-storey house.
If you are booking the work, book the order rather than a single date. Ask for the gutters to be done before the windows, whether that is one visit or two, and send the number of windows, how many are upper floor, and whether the screens are already out when you ask for a quote. Our window cleaning service covers exterior and interior glass, screens and tracks, and you can ask about gutter cleaning in the same request.
Frequently asked questions
What month is best for the last exterior window cleaning in the GTA?
For most houses, late October to mid-November, after the leaves are down and the gutters are cleared. At Toronto Pearson, October averages 25 days with a high above 10 degrees and November only 9, so the later the date, the fewer suitable days are left.
Can windows be cleaned outside when it is below freezing?
Plan the work for a day that stays above freezing into the evening. Water that runs into tracks, sills and weep slots freezes on a cold night, and ice in a sliding track can hold the window shut. Frost on the glass also has to melt and dry before cleaning.
Should I clean the windows or the gutters first in the fall?
The gutters first. Clearing them puts wet debris on the walls and on the glass under the eaves, so washing the windows beforehand means doing the upper glass and sills twice.
When should I turn off the outside tap for winter?
After the last outdoor job that needs water, including the window clean. The City of Toronto advises unscrewing hoses, turning off the outdoor water supply and letting the taps drain, because outdoor faucets are the first to freeze.
Is it a problem to leave the outside of the windows dirty over winter?
The glass itself will come to no harm. What matters before winter is that the weep slots, sills and sliding tracks are clear of leaves and grit, because those hold water against the frame. If you run out of good days, do those and leave the glass for spring.
Sources
- Environment and Climate Change Canada — Canadian Climate Normals 1991–2020, Toronto Pearson (Airport) — Monthly average daily high and low, days with a maximum above 10 °C, days with a minimum at or below 0 °C, days with rainfall of 0.2 mm or more, days with winds of 52 km/h or more, and the average date of first fall frost (October 20).
- Town of Oakville — Loose Leaf Collection — The 2026 loose leaf collection programme runs from October 26 to December 4, by zone.
- City of Toronto — Prevent or Thaw Frozen Pipes — Outdoor faucets are the first to freeze: unscrew hoses, turn off the outdoor water supply and let the taps drain.
- Canadian Centre for Occupational Health and Safety — Ladders, portable — Do not use ladders on ice, mud or other slippery surfaces; avoid climbing with wet soles.
