Reconciling Window Cleaning With Rain in the Forecast

There’s A Chance of Rain in the Forecast!

Rain, or snow, is the legendary and perceived enemy of a window cleaning schedule! From what I’ve read in various industry groups on Facebook and forums, the alarms go off in the heads of customers at varying levels of probability for precipitation. Some in southern California say that clients will postpone their window cleaning appointments if there is a 5% chance of precipitation. I can’t personally confirm or deny that. I don’t know that official forecasts go lower than 20% even in arid regions of the US, but the point seems to be that in areas where homeowners are accustomed to clear days as a rule, even the slightest mention of rain may be a dealbreaker.

Photo of Albert Hammond's album "It never rains in California"

I’ve also gathered from window cleaning and pressure washing companies in the Pacific Northwest that if they allowed the precipitation forecast to strictly guide their schedule, they wouldn’t have a business. On average, in Seattle, Washington it rains somewhere around 150 days per year, but it seems to be more frequent than heavy. It clearly depends on local tolerance for precipitation. Here in northeastern Pennsylvania, a chance of precipitation is pretty common, but not necessarily a daily concern. I checked with my local National Weather Service office and they said the lowest probability of precipitation they will mention on their website’s forecast is 20%. They mentioned that on social media posts they may say as low as 10%. Either way, rain is a potential factor.

 So, Does Rain Make Windows Dirty?

In my years of interacting with residential customers and even passersby when cleaning storefront windows, countless people will say something such as “it’s going to rain later this week and ruin all your work”, “it’s going to rain tomorrow. At least I’ll get one day of clean windows!”, or “you know it’ll rain tomorrow since you’re cleaning the windows!” Thus, the question of whether rain truly makes clean windows dirty and how to address it looms large in the minds of many window cleaners. Such an assertion has become about as common as ‘if I go skiing or snowboarding, I’ll break my leg’. Here is something to think about. Rain itself is pretty clean and pure in its falling state. That does not mean there are no minerals or any other solid matter in it. Technically, pure water (comprising nothing but H₂O) does not exist in nature. It can only be manufactured by distilling or other methods. But it does mean that there are no chemicals or contaminants in typical rainwater- chlorine and so on. There still must be a reason why the fear that rain that falls within days after a window gets cleaned is going to ruin the whole proposition. No question, in certain cases, windows can look pretty awful after being cleaned and then subject to a rainstorm. How do we reconcile the belief with the reality?

What Makes Windows Dirty After It Rains?

As roughly explained above, by and large, rainwater itself is extremely clean and does not mess up clean windows without other factors entering in. A popular saying with professional window cleaners is “Rain doesn’t make windows dirty. Dirt makes windows dirty.”  If stated the wrong way, this may come across as patronizing. However, it pretty much is the deal. Granted, in some areas such as heavily industrialized locales, there may be a high level of contaminants in the atmosphere which raindrops will pick up and deposit on glass. This would be a potential issue. Other added factors that can make windows look dirtier after a good rain are as follows:

filthy frames or siding above the glass – this is a solid reason to also have a good program to maintain the cleanliness of the building itself. When cleaning companies offer power washing and window cleaning, the power washing always is done first. Any legitimate window cleaning company, in my opinion, will clean the frames and openings that are part of the window at the very least. In this way, it will eliminate or greatly minimize the potential for dirty water from above to mess up clean glass.

very windy conditions after a cleaning – in fairness, if there is a significant chance of high winds kicking dirt around following a window cleaning, rescheduling might be the best option. A growing number of companies -mine included- use purified water to clean outside windows. The pure water is applied through some type of jets that use gentle pressure along with a brush or pad to scrub the glass thoroughly. Then, the loose dirt and debris is rinsed off the glass with the same pure water, leaving no dirt on the glass. The fact is that the pure water will take a little time to disappear from the glass, by gravity and evaporation. If wind and dust are present, there may be an issue with the remaining water droplets picking up the blowing dust or dirt. This will be a judgment call that an honest company will have to make as to whether it’s best to reschedule or use the more traditional method of drying the glass right away with a squeegee and detail rag.

dirty window screens – many windows such as double-hungs, single-hungs, and storm panels may be accompanied by screens that are outside of the glass, not inside the house. Screens, by design, keep insects out and collect some of the airborne particulates. When it rains, though, screens that have not been properly cleaned as part of the window cleaning service, will give up some of the junk on them and the junk will be deposited on the glass behind them. So, either leaving your screens out or making sure they are thoroughly cleaned, is the key to keeping the glass clean as long as possible.

splashing water near ground level window panes – sometimes the lower areas of ground level windows are in close proximity to a considerable amount of loose dirt. Perhaps landscaping is not completed or simply not present near some glass, and so persistent water falling onto dirt nearby can splash mud, in essence, onto the glass.

clogged gutters or downspouts causing water spills – it often does not take much of an obstruction somewhere in a run of gutter or at the downspout to cause water to back up. If the rate of backup exceeds the rate of proper flow through the gutter system, enough rainfall will cause water to spill over and out of the gutter at any point before the obstruction. The spilling water will either work its way down the siding of simply free fall somewhere beyond the siding. Strong wind or further physical objects below the gutters may divert some dirty water onto glass. Really, then, just as important as regular maintenance of the siding, is the regular monitoring of how the gutters are working.

We Don’t Live in a Perfect World

Ultimately, clean windows will eventually get dirty. Even the highly-touted ‘self-cleaning’ windows don’t promise to never need attention again. Go figure! Many window cleaning companies, including mine, for this reason offer some type of ‘rain guarantee’. This guarantee promises that if rainfall after cleaning makes some of your windows dirty up to xx days after service, we will return and reclean such windows at no charge. This should help put a homeowner’s fears at ease and also keep the cleaning company’s schedule as intact as reasonably possible. When you think about it, if the chance of rain is the sole factor in deciding when ones windows should be cleaned, there are few regions in the world where it would be considered feasible to even bother. I myself have offered a 5-day rain guarantee for probably 20 years and have only been called to return once or twice that I can recall. That’s fair and expected, since we don’t live in a perfect world!

What Reasons Are There Not to Cancel an Appointment if There is a Slight Chance of Rain?

As previously reasoned out, a window cleaning company that is completely at the mercy of possible rain in the forecast within lets say the next week, would be in pretty rough shape in most parts of the world. The hard truth is that unless you live in an extremely arid region, it will rain and probably rain will touch your windows within a week or two. I have found that most homeowners will eventually accept this if they don’t already. It has also been established that under typical circumstances, rainwater itself does not leave clean windows dirty. If the mitigating circumstances listed above are not present, there should be no issue with cleaning windows before rain is coming or even during a very light rain or drizzle. Another reason, tough as it may be to consider, is that it is not always easy to reschedule an appointment the next day or exactly when a homeowner requests. This all depends on some factors such as how much wiggle room the contractor has, where the company will be in the next few days. Where there is a hard deadline, such as a graduation party, wedding reception, big family gathering, or something else, it may become a very difficult dilemma to solve.

If you have any questions or want to discuss this subject you can email me at
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