Pre-Rainy-Season Window Checklist for Portland Homes

The National Weather Service marks November through March as the Willamette Valley’s wettest stretch, which makes October the last reliable window for exterior maintenance. Here’s what’s worth checking before the rain sets in.

The Checklist

• Clean the glass, inside and out. Summer dust and any accumulated grime is easiest to remove now, before rain turns it into mineral film that’s harder to shift.
• Clear tracks and sills. Debris sitting in a track can trap moisture once the rain starts, which is worse for the frame than dry debris.
• Check storm windows. If your home has them, this is the time to confirm they’re seated properly and sealing well before winter weather tests them.
• Inspect for early moss growth. Shaded, damp-prone areas of glass and frames can start showing moss before the rain even peaks — catching it early is easier than removing an established patch later.
• Clean screens before storing or leaving them in place. A screen that goes into winter dirty tends to come out the other side worse.

Why This Timing Matters

Once the rainy season is fully underway, exterior cleaning becomes less effective — you’re fighting active rain rather than working with dry conditions. A pre-October clean is the last real opportunity to start winter with clear glass instead of a head start on grime.