Portland Weather in September
Portland in September sees high daytime temperatures of 24°C (75°F) and nighttime lows of 12°C (54°F). Moderate rainfall is typical, with around 41 mm (1.6 in) for the month.
Rainfall in Portland in September
Historically, the month has about 8 days of rain, averaging 41 mm (1.6 in) in total. Rain this month is fairly typical, a standard mix of wet and dry days with no particularly heavy or persistent showers.
Temperature in Portland in September
Weather in Portland is at its perfect in September. Highs reach 24°C (75°F), while nights settle around 12°C (54°F). September is part of the summer season. Conditions stay fairly consistent through the month, making it easier to plan what to wear. Nights drop to around 12°C (54°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.
Sunshine in Portland in September
Enjoy a sunny month with about 236 hours of sunshine, the clear skies make Portland even more beautiful.
Wind Speed in Portland in September
Wind speeds average 2 m/s (4 knots) during September. At this speed, expect light breezes that you can feel on your face and cause leaves to rustle gently. Since this is an average, some days are calmer with barely any wind while others have more noticeable gentle breezes.If you're inclined towards comfortable temperatures and drier conditions, September is a good time to visit Portland.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Portland's climate page.
Portland Temperature in September
Min Temperature
12°C (54°F)
Max Temperature
24°C (75°F)
Chance of Rain
27%
Precipitation
41 mm (1.6 in)
Rainy days
8 days
Humidity
69%
Windspeed
2 m/s (4 knots)
Sunshine
236 hours
Percentage Sunshine
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Portland typically drop from around 26°C (79°F) at the start of September to approximately 22°C (72°F) by the end. Nights are cool, with lows typically ranging from 11°C (52°F) to 14°C (57°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Portland in September
Browse day-by-day weather records for Portland spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Portland historical weather extremes in September
Based on 49 years of weather observations in Portland between 1976 and 2025, these are the recorded extremes.
- The hottest September day on record in Portland reached 40°C (104°F) (September 2, 1988).
- Portland experienced its chilliest September day on September 29, 2019, reaching only 11°C (52°F).
- The coldest night in September in Portland was on September 23, 2000, with a minimum of 4°C (39°F).
Best Places in the United States of America in September
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in September →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Portland in September
For Portland in September, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. Rain is likely on several days, so bring a good rain jacket. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.What To Do in Portland in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Portland's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed
See the full Portland climate overview or explore weather in the United States of America.
