Portland Weather in September

Portland in September averages 15°C (59°F) during the day and 10°C (50°F) at night. Keep in mind that quite a bit of rainfall is expected this month.

Rainfall in Portland in September

Historically, September sees about 10 days of rain, with a monthly average of 90 mm (3.5 in). When it rains this month, it tends to come down fairly heavily. Showers can be substantial even if they don't last all day.

Temperature in Portland in September

September in Portland brings typical temperatures with highs around 15°C (59°F) and lows of 10°C (50°F). A light jacket or extra layer can be useful, especially outside the warmest hours of the day. Nights drop to around 10°C (50°F), which is noticeably cooler than the daytime. A light jacket for the evening is a sensible addition, and the cool nights tend to make sleeping comfortable.

For Portland itself, January, February and March generally stand out with the best circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.