What is the weather like in Portland vs Seattle in September?

In September, Portland averages 24°C high / 14°C low with about 46 mm of rain; Seattle averages 21°C high / 12°C low with about 36 mm.

Portland vs Seattle in September

Portland is the better pick in September — 94 vs 89 on SeasonMap's comfort score. Portland is warm, a little rain, clean air, while Seattle is nice, a little rain, clean air.

Portland vs Seattle — September climate, side by side

	🇺🇸 Portland	🇺🇸 Seattle
Comfort score	94/100 (S)	89/100 (A)
Feels-like high	24°C	21°C
Avg high / low	24° / 14°	21° / 12°
Rainfall	46 mm	36 mm
Rainy days	5	6
Humidity	67%	75%
Air quality (AQI)	33	40

Monthly climate normals (ERA5 reanalysis). Comfort scores are SeasonMap estimates.

Month by month

Portland vs Seattle in September — FAQ

Is September better in Portland or Seattle?: Portland is the better pick in September — 94 vs 89 on SeasonMap's comfort score. Portland is warm, a little rain, clean air, while Seattle is nice, a little rain, clean air.
What is the weather like in Portland vs Seattle in September?: In September, Portland averages 24°C high / 14°C low with about 46 mm of rain; Seattle averages 21°C high / 12°C low with about 36 mm.