Weather in Portland for September 2026
Until now, September 2026 in Portland has been nearly identical to the historical average, with a temperature of 17.9 °C (showing only a slight deviation of 0.2 °C).
The forecast for the next days in Portland predicts temperatures to be around 18 °C, close to the historical average.
In general, the average temperature in Portland at the beginning of September is 18.3 °C. As the month progressed, temperatures tended to moderately fall, reaching an average of 17.4 °C by the end of September.
The climate of Portland in September is notably wet, with an average of 15 rainy days, and a total of 83.2 mm of precipitation.
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Portland Weather September
Temperatures trend during September in Portland
September weather in Portland day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Light rain shower | 17° /15° | 4 mm | 2 | |
| 2 Sept. | Light rain shower | 18° /16° | 4 mm | 3 | |
| 3 Sept. | Light rain shower | 18° /17° | 4.5 mm | 1 | |
| 4 Sept. | Light rain shower | 19° /15° | 7.7 mm | 2 | |
| 5 Sept. |  Overcast | 17° /14° | 0 mm | 4 | |
| 6 Sept. | Overcast | 20° /16° | 0.1 mm | 4 | |
| 7 Sept. |  Light drizzle | 19° /16° | 0.7 mm | 3 | |
| 8 Sept. | Patchy rain possible | 17° /14° | 12.4 mm | 4 | |
| 9 Sept. | Light drizzle | 17° /14° | 1.7 mm | 3 | |
| 10 Sept. | Light rain shower | 17° /13° | 2.2 mm | 2 | |
| 11 Sept. | Patchy light drizzle | 17° /14° | 2.7 mm | 2 | |
| 12 Sept. | Light rain shower | 17° /13° | 2.9 mm | 2 | |
| 13 Sept. | Light rain shower | 17° /15° | 4 mm | 2 | |
| 14 Sept. | Light rain shower | 19° /15° | 1.9 mm | 3 | |
| 15 Sept. | Patchy light drizzle | 18° /14° | 0.8 mm | 3 | |
| 16 Sept. | Patchy light drizzle | 17° /13° | 0.4 mm | 3 | |
| 17 Sept. | Patchy rain possible | 18° /14° | 1.8 mm | 1 | |
| 18 Sept. | Patchy rain possible | 17° /15° | 0.2 mm | 2 | |
| 19 Sept. | Overcast | 18° /15° | 0 mm | 3 | |
| 20 Sept. | Overcast | 18° /16° | 0.5 mm | 3.8 | |
| 21 Sept. |  Sunny | 18° /15° | 0 mm | 4.2 | |
| 22 Sept. | Sunny | 18° /17° | 0 mm | 4.1 | |
| 23 Sept. | Overcast | 20° /16° | 0 mm | 3.4 | |
| 24 Sept. | Patchy rain possible | 17° /15° | 0.2 mm | 4 | |
| 25 Sept. | Sunny | 17° /16° | 0 mm | 5 | |
| 26 Sept. | Overcast | 17° /16° | 0 mm | 4 | |
| 27 Sept. | Sunny | 19° /17° | 0 mm | 5 | |
| 28 Sept. | Sunny | 18° /15° | 1.3 mm | 5 | |
| 29 Sept. | Patchy rain possible | 16° /15° | 0.9 mm | 5 | |
| 30 Sept. | Sunny | 18° /16° | 0 mm | 5 | |
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Portland in September - FAQ
What are the expected maximum and minimum temperatures in Portland during September?
How much rainfall should be expected in Portland during September?
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September rainfall patterns in Portland
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