Portland in December
December in Portland is peak summer, and the weather reflects it. You're looking at average daily highs of 21.5 degrees.
The average daily maximum is 21.5 degrees with overnight lows of 13.2 degrees. Comfortable during the day, with evenings that invite a light layer.
December is 3.6 degrees warmer than the yearly average here.
The rain data says 41mm over 7 days. Nothing dramatic.
Solar exposure averages 24.2 MJ/m2 per day in December, with UV levels in the extreme range. Sunscreen, hat, and sunnies are all essential. You can burn in under 10 minutes.
Our Comfort Score rates December at 9.1/10. That's about as good as it gets.
Packing tip: bring a decent jumper or fleece, and serious sun protection.
The full data breakdown is below. You can also see how other Australian cities compare in December.
December at a Glance
Temperature Range
Daily temperature range in December. The bar shows the typical spread between overnight lows and afternoon highs.
What to Pack
- Layered clothing for mild to cool conditions
- A light rain jacket just in case
- High SPF sunscreen (50+), sunglasses, and UV-protective clothing
Coming From Overseas?
How December in Portland stacks up against major cities around the world.
About 14 degrees warmer and considerably drier.
About 16 degrees warmer and considerably drier.
About 10 degrees warmer and considerably drier.
How December Compares
Portland's monthly climate at a glance. December 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 |