The best time of year to clean windows

Best: overcast, cool and still

The ideal weather for window cleaning is a grey day. In direct sun the water dries on the pane before it can be wiped off, leaving streaks and dried droplets – the same work produces a worse result. An overcast day above freezing is the best moment, whatever the season.

Spring is the most booked – for good reason

After winter, road salt, soot and rain spatter are sitting on the glass, and when the sun returns it all shows at full strength. That is why spring is high season for window cleaning. The drawback is exactly that: demand is high and the slots run out. If you want a time in April or May, book in March.

Summer: good weather, wrong light

Summer is practical – warm, dry, easy to open windows – but don't clean in the middle of a sunny day. Early morning or the evening hours give a better result. Pollen season is worth a thought too: clean before the birch pollen is over and the glass will need doing again.

Autumn: the underrated choice

Autumn is the most overlooked and often the best. Overcast weather is the rule rather than the exception, leaves and pollen are done, and you go into the dark half of the year with clean windows – which is exactly when it shows most, because indoor light reveals every streak. Demand is also lower than in spring.

Winter: possible, but it has requirements

Windows can be cleaned in winter. What doesn't work is plain water below freezing – it freezes on the glass and can damage seals and fittings. Professional cleaners therefore use an antifreeze additive or pick a day above zero. Two things apply:

• Ask how the company handles the cold before booking a winter clean. If you don't get a clear answer, rebook.
• The inside can always be cleaned, all year round. If the outside is impossible right now, half the job can still be done – and in winter it is often the inside that makes the visible difference.

In summary

• Best result: overcast, above freezing, no direct sun.
• Best availability: autumn and late winter.
• Book ahead: spring, where slots go first.
• Avoid: strong sun, high wind, and cleaning just before the peak of pollen season.

See available times for window cleaning and read about what's included.