Portland in September
If September is your window for visiting Portland, here's what the climate data says you can expect.
Daytime highs average 14.8 degrees, dropping to 10.0 degrees overnight. That's a 5-degree swing between day and night. Manageable with a decent layer, and you'll warm up by midday.
September is 3.1 degrees cooler than Portland's yearly average.
The rain data says 90mm over 17 days. A decent amount, but not relentless.
Solar exposure averages 11.8 MJ/m2 per day in September, with UV levels in the high range. Sun protection is still a good idea, especially around midday.
September scores 2.3/10 on our Comfort Score. It's the tough end of the year weather-wise.
For your suitcase: warm layers including a coat, a rain jacket or compact umbrella, and serious sun protection.
The full data breakdown is below. You can also see how other Australian cities compare in September.
September at a Glance
Temperature Range
Daily temperature range in September. The bar shows the typical spread between overnight lows and afternoon highs.
What to Pack
- Winter clothing including a proper coat
- Proper rain gear for frequent showers
Coming From Overseas?
How September in Portland stacks up against major cities around the world.
About 5 degrees cooler and considerably wetter.
About 11 degrees cooler and considerably drier.
About 12 degrees cooler and considerably drier.
How September Compares
Portland's monthly climate at a glance. September is highlighted.
| Month | Max | Min | Rain | Comfort |
|---|---|---|---|---|
| Jan | 21.2 | 14.6 | 71mm | 8.2 |
| Feb | 22.2 | 13.5 | 5mm | 10.0 |
| Mar | 21.9 | 13.7 | 14mm | 9.2 |
| Apr | 16.9 | 11.3 | 54mm | 4.0 |
| May | 15.9 | 9.7 | 23mm | 3.5 |
| Jun | 13.2 | 7.6 | 37mm | 1.5 |
| Jul | 13.0 | 7.4 | 84mm | 1.0 |
| Aug | 16.2 | 9.4 | 70mm | 3.4 |
| Sep | 14.8 | 10.0 | 90mm | 2.3 |
| Oct | 17.7 | 10.4 | 68mm | 5.6 |
| Nov | 19.8 | 12.0 | 91mm | 7.1 |
| Dec | 21.5 | 13.2 | 41mm | 9.1 |