Portland (ME)
September
Weather in Portland, Maine for September 2027
Your guide to Portland weather in September - trends and predictions
In general, the average temperature in Portland at the beginning of September is 20.8 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 17.8 °C by the end of September.
Portland experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 156.6 mm.
Is September a good time to visit Portland? check out the best time to travel to Portland page.
✨ Is September a good time to visit Portland? – Ask the AI Weatherman
Temperatures
Rain 🌧️
More
23
Dry days
7
Rainy days
0
Snow days
19°/13°
Temperatures
18 km/h
Avg max wind
77 %
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 |  Light rain | 21° /15° | 2.6 mm | 4 | |
| Sept. 2 |  Partly cloudy | 19° /14° | 0 mm | 4 | |
| Sept. 3 | Light rain | 19° /12° | 5.9 mm | 4 | |
| Sept. 4 |  Fog | 23° /14° | 0 mm | 5 | |
| Sept. 5 |  Patchy rain possible | 21° /16° | 1.1 mm | 6 | |
| Sept. 6 | Mist | 21° /15° | 0.1 mm | 4 | |
| Sept. 7 | Light rain | 21° /12° | 9.3 mm | 5 | |
| Sept. 8 |  Sunny | 21° /13° | 0.8 mm | 4 | |
| Sept. 9 | Patchy rain possible | 20° /12° | 1.3 mm | 4 | |
| Sept. 10 | Light rain | 23° /14° | 4.2 mm | 4 | |
| Sept. 11 | Sunny | 23° /12° | 0 mm | 6 | |
| Sept. 12 | Partly cloudy | 21° /11° | 0 mm | 6 | |
| Sept. 13 | Light rain | 20° /14° | 2.8 mm | 4 | |
| Sept. 14 | Patchy rain possible | 20° /14° | 0 mm | 5 | |
| Sept. 15 |  Overcast | 19° /13° | 0 mm | 5 | |
| Sept. 16 | Sunny | 20° /13° | 0 mm | 4 | |
| Sept. 17 | Light rain | 19° /13° | 7 mm | 4 | |
| Sept. 18 | Mist | 22° /14° | 0.6 mm | 5 | |
| Sept. 19 | Mist | 18° /12° | 0 mm | 5 | |
| Sept. 20 | Light rain | 17° /11° | 3.8 mm | 3 | |
| Sept. 21 | Patchy rain possible | 17° /12° | 2.2 mm | 3 | |
| Sept. 22 | Overcast | 16° /12° | 0 mm | 3 | |
| Sept. 23 | Overcast | 17° /13° | 0 mm | 4 | |
| Sept. 24 |  Cloudy | 17° /12° | 0 mm | 4 | |
| Sept. 25 |  Moderate rain | 17° /11° | 21.7 mm | 3 | |
| Sept. 26 |  Heavy rain | 19° /15° | 69.2 mm | 3 | |
| Sept. 27 | Moderate rain | 17° /13° | 12.1 mm | 4 | |
| Sept. 28 | Light rain | 17° /14° | 9.7 mm | 3 | |
| Sept. 29 | Patchy rain possible | 19° /13° | 2.2 mm | 4 | |
| Sept. 30 | Cloudy | 18° /14° | 0.1 mm | 4 | |
| Next | |||||
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 19° 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?
Significant rainfall exceeding 156.6 mm is expected in Portland during September, occurring over more than 7 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Portland during September?
The average wind speed in Portland during September is 18 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 7 rainy days in September with a total of 156.6 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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