Portland (OR)
September
Weather in Portland, Oregon for September 2026
Your guide to Portland weather in September - trends and predictions
In general, the average temperature in Portland at the beginning of September is 28.1 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 21.1 °C by the end of September.
The climate of Portland in September is notably wet, with an average of 12 rainy days, and a total of 61.9 mm of precipitation.
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Temperatures
Rain 🌧️
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18
Dry days
12
Rainy days
0
Snow days
24°/13°
Temperatures
10 km/h
Avg max wind
63 %
Avg humidity
Portland Weather September
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Temperatures trend during September in Portland
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September weather in Portland day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Fog | 28° /15° | 0.1 mm | 6 | |
| Sept. 2 |  Cloudy | 28° /15° | 0.1 mm | 7 | |
| Sept. 3 |  Patchy rain possible | 27° /16° | 0.8 mm | 6 | |
| Sept. 4 |  Overcast | 28° /13° | 0.7 mm | 6 | |
| Sept. 5 | Overcast | 32° /16° | 0 mm | 8 | |
| Sept. 6 |  Partly cloudy | 29° /16° | 0 mm | 7 | |
| Sept. 7 | Overcast | 25° /15° | 0 mm | 6 | |
| Sept. 8 | Overcast | 26° /15° | 5.2 mm | 6 | |
| Sept. 9 | Cloudy | 26° /13° | 10.2 mm | 6 | |
| Sept. 10 |  Sunny | 25° /14° | 0 mm | 6 | |
| Sept. 11 | Overcast | 20° /13° | 3.7 mm | 4 | |
| Sept. 12 | Cloudy | 21° /12° | 0.2 mm | 5 | |
| Sept. 13 | Overcast | 24° /11° | 0 mm | 6 | |
| Sept. 14 | Sunny | 25° /12° | 1.4 mm | 6 | |
| Sept. 15 | Sunny | 27° /11° | 0 mm | 7 | |
| Sept. 16 | Sunny | 29° /13° | 0 mm | 7 | |
| Sept. 17 | Overcast | 23° /13° | 4 mm | 6 | |
| Sept. 18 | Overcast | 22° /13° | 0 mm | 5 | |
| Sept. 19 | Overcast | 23° /13° | 0 mm | 6 | |
| Sept. 20 | Light rain shower | 22° /12° | 0.5 mm | 5 | |
| Sept. 21 | Partly cloudy | 23° /10° | 5.7 mm | 6 | |
| Sept. 22 | Sunny | 24° /11° | 0 mm | 6 | |
| Sept. 23 | Light rain shower | 26° /13° | 0.5 mm | 6 | |
| Sept. 24 | Sunny | 27° /14° | 1.4 mm | 7 | |
| Sept. 25 | Light rain shower | 19° /13° | 4.6 mm | 4 | |
| Sept. 26 | Light rain shower | 21° /11° | 3.5 mm | 5 | |
| Sept. 27 | Overcast | 22° /13° | 4.2 mm | 5 | |
| Sept. 28 | Patchy rain possible | 20° /11° | 0.1 mm | 5 | |
| Sept. 29 | Overcast | 18° /11° | 6.6 mm | 4 | |
| Sept. 30 | Partly cloudy | 21° /9° | 8.2 mm | 5 | |
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Important Notice
Our weather forecast for Portland in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Portland forecast closer to your planned date for the most up-to-date weather information.
Change Month
Portland in September - FAQ
What are the expected maximum and minimum temperatures in Portland during September?
Enjoy moderate daytime temperatures of up to 24° and cooler nights around 13°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Portland during September?
Moderate rainfall is anticipated in Portland during September, with a total of 61.9 mm spread over approximately 12 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Portland during September?
The average wind speed in Portland during September is 10 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Portland
Explore the daily rainfall trends and prepare for Portlands September weather 💧
Typically, Portland has 12 rainy days in September with a total of 61.9 mm of rainfall.
UV exposure in Portland during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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