Weather in Portland, Maine for September 2026
Until now, September 2026 in Portland has been nearly identical to the historical average, with a temperature of 21.5 °F (showing only a slight deviation of 0.4 °F).
The forecast for the upcoming days in Portland predicts a temperature of 15 °F, which is slightly above the historical average.
In general, the average temperature in Portland at the beginning of September is 21.3 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 14.4 °F by the end of September.
Portland experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 158.6 mm.
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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 |
|---|---|---|---|---|---|
| Sept. 1 |  Light rain shower | 22° /15° | 2.6 mm | 4 | |
| Sept. 2 |  Partly cloudy | 19° /14° | 0 mm | 4 | |
| Sept. 3 |  Sunny | 19° /12° | 5.9 mm | 4 | |
| Sept. 4 |  Fog | 23° /14° | 0 mm | 5 | |
| Sept. 5 | Sunny | 22° /15° | 1.1 mm | 6 | |
| Sept. 6 | Mist | 22° /14° | 0.1 mm | 4 | |
| Sept. 7 | Mist | 22° /12° | 9.3 mm | 5 | |
| Sept. 8 | Sunny | 21° /12° | 0.8 mm | 4 | |
| Sept. 9 | Sunny | 20° /11° | 1.3 mm | 4 | |
| Sept. 10 | Partly cloudy | 23° /14° | 4.2 mm | 4 | |
| Sept. 11 | Sunny | 23° /11° | 0 mm | 6 | |
| Sept. 12 | Partly cloudy | 22° /11° | 0 mm | 6 | |
| Sept. 13 | Patchy rain possible | 20° /14° | 2.8 mm | 4 | |
| Sept. 14 | Patchy rain possible | 20° /14° | 0 mm | 5 | |
| Sept. 15 |  Overcast | 20° /12° | 0 mm | 5 | |
| Sept. 16 | Sunny | 21° /13° | 0 mm | 4 | |
| Sept. 17 | Fog | 19° /13° | 7 mm | 4 | |
| Sept. 18 | Mist | 22° /13° | 0.6 mm | 5 | |
| Sept. 19 | Mist | 18° /12° | 0 mm | 5 | |
| Sept. 20 | Overcast | 15° /12° | 16 mm | 1.3 | |
| Sept. 21 | Overcast | 17° /12° | 0.7 mm | 5 | |
| Sept. 22 | Overcast | 13° /11° | 0 mm | 3.6 | |
| Sept. 23 | Sunny | 13° /10° | 0.1 mm | 5 | |
| Sept. 24 | Overcast | 14° /10° | 0 mm | 4.2 | |
| Sept. 25 | Overcast | 14° /12° | 9.2 mm | 3 | |
| Sept. 26 | Overcast | 18° /14° | 1.2 mm | 4 | |
| Sept. 27 | Overcast | 14° /9° | 0 mm | 4 | |
| Sept. 28 | Patchy rain possible | 13° /11° | 0.1 mm | 4 | |
| Sept. 29 | Sunny | 14° /10° | 0 mm | 4 | |
| Sept. 30 | Light rain shower | 14° /11° | 7.9 mm | 3 | |
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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?
What are the typical wind conditions in Portland during September?
September rainfall patterns in Portland
UV exposure in Portland during September
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Where is Portland?Get accurate weather forecasts for Portland, located at latitude 43.657 and longitude -70.259. Stay updated with localized weather information tailored for Portland.