The Portland Homeowner’s Window Cleaning Calendar

Portland’s climate doesn’t clean your windows on a fixed schedule, but it does follow a predictable seasonal pattern — and that pattern is the actual basis for when your windows need attention. Here’s the full-year breakdown.

Spring: Pollen and Winter Grime

Cedar and fir pollen coats glass hard every spring, right as winter’s accumulated rain-driven mineral film is still sitting on the surface. This is the first of the two highest-value cleaning windows each year.

Summer: Lower Priority, Higher Visibility

Portland’s dry summer months mean less new grime accumulating, but bright summer light makes any existing streaks or spots far more visible than they were under winter cloud cover.

Early Fall: The Pre-Rain Window

This is the second critical cleaning point. The National Weather Service marks the Willamette Valley’s wettest stretch as running from November through March, which makes October the last reliable window for exterior maintenance before the rainy season sets in. See our pre-rainy-season checklist for specifics.

Winter: Rain, Not Cleaning

Rain doesn’t clean your windows — it deposits mineral film and pushes grime into corners and tracks. Winter is the season your fall cleaning is protecting against, not a time to expect much natural upkeep.

Wildcard: Wildfire Season

In recent wildfire seasons, ash has settled on glass across the Portland metro. It’s highly alkaline and, left too long, can affect glass porosity — more on that in our wildfire ash guide.

The Bottom Line

Two cleanings a year — spring and early fall — covers most Portland homes. Heavier tree cover, riverside humidity, or a lot of west-facing glass can push that higher.