The answer to 'how long does window cleaning last' is that the duration of window cleaning depends on several factors, but generally, professional window cleaning can last 6-12 months before needing to be repeated. This timeframe can vary based on factors like the climate, location, and how dirty the windows get over time.
For example, windows in areas with heavy pollution, frequent storms, or lots of tree cover may need cleaning more often, perhaps every 3-6 months. Meanwhile, windows in less exposed areas may only need cleaning once a year. Regular DIY cleaning in between professional services can also help extend the time between full cleanings.