Portland weather in September
In September, Portland sees average daytime highs of 87°F and overnight lows near 75°F, with 4.3 in of rain across 13.8 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 1st-wettest month of the year here.
Highs ease over the month, from about 88°F in the first days to 85°F by the end. The sky is clear or mostly clear about 47% of the time in September, and the air most often feels miserable.
Daylight stretches from about 12 h 36 min at the start of September to 11 h 48 min by month's end. Set against the rest of the year, September is Portland's 6th-clearest and 12th-windiest month. For the whole year in context, see Portland's year-round climate.
- Daytime high
- 87°
- 4th warmest
- Overnight low
- 75°
- 9th coldest
- Rainfall
- 4.3 in
- 13.8 wet days
- Daylight
- 12 h 12 min
- 6:19 AM – 6:29 PM
- Cloud cover
- 49%
- 6th clearest
- Wind
- 9 mph
- 12th windiest
- Solar energy
- 5.14 kWh/m²
- Travel score
- 4.5
- out of 10
Portland is city in Texas, United States.
- Density
- 580/km²
- people per km²
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in September
Highs ease over the month, from about 88°F in the first days to 85°F by the end.
A typical September day in Portland reaches about 87°F in the afternoon and slips back to 75°F overnight — a 12°F spread between the day's warmth and the night's chill. On most days the high lands between 82°F and 90°F. Set against its neighbours, September runs about 3°F cooler than August and about 6°F warmer than October.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 89 | 89 | 89 | 88 | 88 | 88 | 88 | 88 | 88 | 87 | 87 | 87 | 87 | 87 | 87 | 87 | 87 | 87 | 86 | 86 | 86 | 86 | 86 | 86 | 85 | 85 | 85 | 85 | 85 | 85 |
| Avg low (°F) | 77 | 77 | 77 | 77 | 77 | 77 | 77 | 76 | 76 | 76 | 76 | 76 | 76 | 76 | 75 | 75 | 75 | 75 | 74 | 74 | 74 | 74 | 73 | 73 | 73 | 73 | 72 | 72 | 72 | 72 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 89 | 77 |
| 2 | 89 | 77 |
| 3 | 89 | 77 |
| 4 | 88 | 77 |
| 5 | 88 | 77 |
| 6 | 88 | 77 |
| 7 | 88 | 77 |
| 8 | 88 | 76 |
| 9 | 88 | 76 |
| 10 | 87 | 76 |
| 11 | 87 | 76 |
| 12 | 87 | 76 |
| 13 | 87 | 76 |
| 14 | 87 | 76 |
| 15 | 87 | 75 |
| 16 | 87 | 75 |
| 17 | 87 | 75 |
| 18 | 87 | 75 |
| 19 | 86 | 74 |
| 20 | 86 | 74 |
| 21 | 86 | 74 |
| 22 | 86 | 74 |
| 23 | 86 | 73 |
| 24 | 86 | 73 |
| 25 | 85 | 73 |
| 26 | 85 | 73 |
| 27 | 85 | 72 |
| 28 | 85 | 72 |
| 29 | 85 | 72 |
| 30 | 85 | 72 |
How September really feels in Portland
Once humidity and wind are folded in, September averages 28 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.
The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Portland weather by month
How September compares with the rest of the year at a glance. September is the 4th-warmest and 1st-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 65° / 51° | 2.1 | 6.5 | 10.4 | 6.5 |
| Feb | 68° / 54° | 1.5 | 5.2 | 11 | 6.9 |
| Mar | 73° / 60° | 2.2 | 6.2 | 11.8 | 7.4 |
| Apr | 78° / 66° | 2.0 | 6.4 | 12.6 | 7.4 |
| May | 83° / 73° | 2.7 | 8.8 | 13.4 | 6.1 |
| Jun | 87° / 77° | 2.9 | 10.2 | 13.7 | 4.8 |
| Jul | 89° / 78° | 2.2 | 8.6 | 13.6 | 4.5 |
| Aug | 89° / 78° | 2.3 | 9.7 | 13 | 4.2 |
| Sep | 87° / 75° | 4.3 | 13.8 | 12.2 | 4.5 |
| Oct | 81° / 67° | 3.4 | 8.8 | 11.3 | 6.8 |
| Nov | 73° / 59° | 2.2 | 6.8 | 10.6 | 7.4 |
| Dec | 67° / 52° | 2.1 | 6.3 | 10.3 | 6.7 |
Cloud cover in September
The sky is clear or mostly clear about 47% of the time in September.
Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 38%. Skies tend to open up as the month goes on.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 57 | 57 | 57 | 56 | 57 | 56 | 56 | 57 | 57 | 57 | 57 | 58 | 58 | 59 | 60 | 60 | 61 | 62 | 63 | 64 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 73 | 73 |
| Cloudier (%) | 43 | 43 | 43 | 44 | 43 | 44 | 44 | 43 | 43 | 43 | 43 | 42 | 42 | 41 | 40 | 40 | 39 | 38 | 37 | 36 | 34 | 33 | 32 | 31 | 30 | 29 | 28 | 27 | 27 | 27 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 57 | 43 |
| 2 | 57 | 43 |
| 3 | 57 | 43 |
| 4 | 56 | 44 |
| 5 | 57 | 43 |
| 6 | 56 | 44 |
| 7 | 56 | 44 |
| 8 | 57 | 43 |
| 9 | 57 | 43 |
| 10 | 57 | 43 |
| 11 | 57 | 43 |
| 12 | 58 | 42 |
| 13 | 58 | 42 |
| 14 | 59 | 41 |
| 15 | 60 | 40 |
| 16 | 60 | 40 |
| 17 | 61 | 39 |
| 18 | 62 | 38 |
| 19 | 63 | 37 |
| 20 | 64 | 36 |
| 21 | 66 | 34 |
| 22 | 67 | 33 |
| 23 | 68 | 32 |
| 24 | 69 | 31 |
| 25 | 70 | 30 |
| 26 | 71 | 29 |
| 27 | 72 | 28 |
| 28 | 73 | 27 |
| 29 | 73 | 27 |
| 30 | 73 | 27 |
Chance of precipitation in September
Portland gets around 4.3 in of rain over 13.8 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 45% and peaks near 53% on the wettest days. The odds ease toward the end of the month.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 50 | 51 | 51 | 52 | 53 | 53 | 53 | 53 | 53 | 52 | 52 | 51 | 51 | 50 | 49 | 48 | 47 | 46 | 44 | 43 | 41 | 40 | 38 | 37 | 35 | 34 | 33 | 32 | 31 | 31 |
| Rain chance (%) | |
|---|---|
| 1 | 50 |
| 2 | 51 |
| 3 | 51 |
| 4 | 52 |
| 5 | 53 |
| 6 | 53 |
| 7 | 53 |
| 8 | 53 |
| 9 | 53 |
| 10 | 52 |
| 11 | 52 |
| 12 | 51 |
| 13 | 51 |
| 14 | 50 |
| 15 | 49 |
| 16 | 48 |
| 17 | 47 |
| 18 | 46 |
| 19 | 44 |
| 20 | 43 |
| 21 | 41 |
| 22 | 40 |
| 23 | 38 |
| 24 | 37 |
| 25 | 35 |
| 26 | 34 |
| 27 | 33 |
| 28 | 32 |
| 29 | 31 |
| 30 | 31 |
Humidity in September
Most of September feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, September lands in the miserable band about 47% of days. Sticky, muggy-or-worse air turns up on roughly 90% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 4 | 4 | 4 |
| Comfortable (%) | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 4 | 4 | 5 | 5 | 5 | 6 | 6 | 6 | 7 | 7 |
| Humid (%) | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 4 | 4 | 4 | 5 | 5 | 6 | 7 | 8 | 8 | 9 | 10 | 11 | 12 | 12 | 13 | 14 | 14 |
| Muggy (%) | 4 | 5 | 5 | 5 | 5 | 5 | 6 | 6 | 6 | 7 | 7 | 8 | 8 | 9 | 10 | 10 | 11 | 12 | 12 | 13 | 14 | 15 | 15 | 16 | 16 | 17 | 17 | 18 | 18 | 18 |
| Oppressive (%) | 30 | 31 | 32 | 33 | 33 | 34 | 35 | 35 | 35 | 35 | 35 | 35 | 35 | 34 | 34 | 34 | 34 | 34 | 33 | 32 | 32 | 31 | 31 | 30 | 30 | 30 | 31 | 31 | 31 | 31 |
| Miserable (%) | 65 | 63 | 62 | 61 | 60 | 58 | 56 | 56 | 56 | 55 | 54 | 53 | 53 | 51 | 50 | 49 | 47 | 46 | 44 | 43 | 41 | 39 | 38 | 36 | 34 | 32 | 30 | 29 | 27 | 25 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| 1 | 0 | 0 | 1 | 4 | 30 | 65 |
| 2 | 0 | 0 | 1 | 5 | 31 | 63 |
| 3 | 0 | 0 | 1 | 5 | 32 | 62 |
| 4 | 0 | 0 | 1 | 5 | 33 | 61 |
| 5 | 0 | 1 | 1 | 5 | 33 | 60 |
| 6 | 0 | 1 | 2 | 5 | 34 | 58 |
| 7 | 0 | 1 | 2 | 6 | 35 | 56 |
| 8 | 0 | 1 | 2 | 6 | 35 | 56 |
| 9 | 0 | 1 | 2 | 6 | 35 | 56 |
| 10 | 0 | 1 | 2 | 7 | 35 | 55 |
| 11 | 0 | 1 | 3 | 7 | 35 | 54 |
| 12 | 0 | 1 | 3 | 8 | 35 | 53 |
| 13 | 0 | 1 | 3 | 8 | 35 | 53 |
| 14 | 0 | 2 | 4 | 9 | 34 | 51 |
| 15 | 0 | 2 | 4 | 10 | 34 | 50 |
| 16 | 1 | 2 | 4 | 10 | 34 | 49 |
| 17 | 1 | 2 | 5 | 11 | 34 | 47 |
| 18 | 1 | 3 | 5 | 12 | 34 | 46 |
| 19 | 1 | 3 | 6 | 12 | 33 | 44 |
| 20 | 2 | 3 | 7 | 13 | 32 | 43 |
| 21 | 2 | 4 | 8 | 14 | 32 | 41 |
| 22 | 2 | 4 | 8 | 15 | 31 | 39 |
| 23 | 2 | 5 | 9 | 15 | 31 | 38 |
| 24 | 3 | 5 | 10 | 16 | 30 | 36 |
| 25 | 3 | 5 | 11 | 16 | 30 | 34 |
| 26 | 3 | 6 | 12 | 17 | 30 | 32 |
| 27 | 3 | 6 | 12 | 17 | 31 | 30 |
| 28 | 4 | 6 | 13 | 18 | 31 | 29 |
| 29 | 4 | 7 | 14 | 18 | 31 | 27 |
| 30 | 4 | 7 | 14 | 18 | 31 | 25 |
Wind in September
Winds average 9 mph in September, the calmest month.
Across September, daily wind ranges from about 9 mph on the calmest days to 9 mph at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 |
| Feels | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze |
| Wind speed (mph) | Feels | |
|---|---|---|
| 1 | 9 | light breeze |
| 2 | 9 | light breeze |
| 3 | 9 | light breeze |
| 4 | 9 | light breeze |
| 5 | 9 | light breeze |
| 6 | 9 | light breeze |
| 7 | 9 | light breeze |
| 8 | 9 | light breeze |
| 9 | 9 | light breeze |
| 10 | 9 | light breeze |
| 11 | 9 | light breeze |
| 12 | 9 | light breeze |
| 13 | 9 | light breeze |
| 14 | 9 | light breeze |
| 15 | 9 | light breeze |
| 16 | 9 | light breeze |
| 17 | 9 | light breeze |
| 18 | 9 | light breeze |
| 19 | 9 | light breeze |
| 20 | 9 | light breeze |
| 21 | 9 | light breeze |
| 22 | 9 | light breeze |
| 23 | 9 | light breeze |
| 24 | 9 | light breeze |
| 25 | 9 | light breeze |
| 26 | 9 | light breeze |
| 27 | 9 | light breeze |
| 28 | 9 | light breeze |
| 29 | 9 | light breeze |
| 30 | 9 | light breeze |
Sunrise & sunset in September
Daylight runs from about 12 h 36 min at the start of September to 11 h 48 min by month's end. The lit band spans sunrise to sunset each day.
Days shrink by about 48 minutes over September. Sunrise moves from 6:12 AM to 6:26 AM, and sunset from 6:46 PM to 6:12 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 12.6 | 12.6 | 12.5 | 12.5 | 12.5 | 12.4 | 12.4 | 12.4 | 12.4 | 12.3 | 12.3 | 12.3 | 12.2 | 12.2 | 12.2 | 12.2 | 12.1 | 12.1 | 12.1 | 12.0 | 12.0 | 12.0 | 12.0 | 11.9 | 11.9 | 11.9 | 11.9 | 11.8 | 11.8 | 11.8 |
| Sunrise (AM) | 6:12 | 6:12 | 6:12 | 6:13 | 6:13 | 6:14 | 6:14 | 6:15 | 6:15 | 6:16 | 6:16 | 6:17 | 6:17 | 6:18 | 6:18 | 6:19 | 6:19 | 6:20 | 6:20 | 6:21 | 6:21 | 6:22 | 6:22 | 6:23 | 6:23 | 6:24 | 6:24 | 6:25 | 6:25 | 6:26 |
| Sunset (PM) | 6:46 | 6:45 | 6:44 | 6:43 | 6:42 | 6:41 | 6:39 | 6:38 | 6:37 | 6:36 | 6:35 | 6:33 | 6:32 | 6:31 | 6:30 | 6:29 | 6:27 | 6:26 | 6:25 | 6:24 | 6:22 | 6:21 | 6:20 | 6:19 | 6:18 | 6:16 | 6:15 | 6:14 | 6:13 | 6:12 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.6 | 6:12 | 6:46 |
| 2 | 12.6 | 6:12 | 6:45 |
| 3 | 12.5 | 6:12 | 6:44 |
| 4 | 12.5 | 6:13 | 6:43 |
| 5 | 12.5 | 6:13 | 6:42 |
| 6 | 12.4 | 6:14 | 6:41 |
| 7 | 12.4 | 6:14 | 6:39 |
| 8 | 12.4 | 6:15 | 6:38 |
| 9 | 12.4 | 6:15 | 6:37 |
| 10 | 12.3 | 6:16 | 6:36 |
| 11 | 12.3 | 6:16 | 6:35 |
| 12 | 12.3 | 6:17 | 6:33 |
| 13 | 12.2 | 6:17 | 6:32 |
| 14 | 12.2 | 6:18 | 6:31 |
| 15 | 12.2 | 6:18 | 6:30 |
| 16 | 12.2 | 6:19 | 6:29 |
| 17 | 12.1 | 6:19 | 6:27 |
| 18 | 12.1 | 6:20 | 6:26 |
| 19 | 12.1 | 6:20 | 6:25 |
| 20 | 12.0 | 6:21 | 6:24 |
| 21 | 12.0 | 6:21 | 6:22 |
| 22 | 12.0 | 6:22 | 6:21 |
| 23 | 12.0 | 6:22 | 6:20 |
| 24 | 11.9 | 6:23 | 6:19 |
| 25 | 11.9 | 6:23 | 6:18 |
| 26 | 11.9 | 6:24 | 6:16 |
| 27 | 11.9 | 6:24 | 6:15 |
| 28 | 11.8 | 6:25 | 6:14 |
| 29 | 11.8 | 6:25 | 6:13 |
| 30 | 11.8 | 6:26 | 6:12 |
Solar energy in September
Average shortwave solar energy reaching the ground each day in September, about 5.14 kWh/m².
For context, solar energy here swings from a low near 2.76 kWh/m² to a high of 6.6 kWh/m² in July across the year — September's 5.14 kWh/m² falls in the middle.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.5 | 5.5 | 5.4 | 5.4 | 5.4 | 5.3 | 5.3 | 5.3 | 5.2 | 5.2 | 5.2 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.1 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 5.5 | Bright |
| 2 | 5.5 | Bright |
| 3 | 5.4 | Bright |
| 4 | 5.4 | Bright |
| 5 | 5.4 | Bright |
| 6 | 5.3 | Bright |
| 7 | 5.3 | Bright |
| 8 | 5.3 | Bright |
| 9 | 5.2 | Bright |
| 10 | 5.2 | Bright |
| 11 | 5.2 | Bright |
| 12 | 5.1 | Bright |
| 13 | 5.1 | Bright |
| 14 | 5.1 | Bright |
| 15 | 5.1 | Bright |
| 16 | 5.1 | Bright |
| 17 | 5.1 | Bright |
| 18 | 5.0 | Bright |
| 19 | 5.0 | Bright |
| 20 | 5.0 | Bright |
| 21 | 5.0 | Bright |
| 22 | 5.0 | Bright |
| 23 | 5.0 | Bright |
| 24 | 5.0 | Bright |
| 25 | 5.0 | Bright |
| 26 | 5.0 | Bright |
| 27 | 5.0 | Bright |
| 28 | 5.0 | Bright |
| 29 | 5.0 | Bright |
| 30 | 5.0 | Bright |
Hazard calendar for Portland
In September, Portland sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.
Portland sits in the Atlantic hurricane belt; the season peaks August–October.
Is September a good time to visit Portland?
Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
September is a reasonable time to visit Portland for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Portland in September
From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In September, Portland sees daytime highs around 87°F and nights near 75°F. Pack light clothes and rain gear. Worth having: sun protection. About 14 days see rain.
Sea temperature near Portland in September
The nearest coast averages about 84°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 21 mi away) is warmest in September at about 84°F and coldest in February near 64°F.
It's comfortable for a long swim from Mar 29 to Dec 20 — about 8.8 months when the water holds above 68°F.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 65 | 64 | 66 | 71 | 77 | 82 | 83 | 84 | 84 | 80 | 73 | 69 |
| Comfort | Cool | Cool | Cool | Refreshing | Warm | Tropical | Tropical | Tropical | Tropical | Warm | Refreshing | Refreshing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 65 | Cool |
| Feb | 64 | Cool |
| Mar | 66 | Cool |
| Apr | 71 | Refreshing |
| May | 77 | Warm |
| Jun | 82 | Tropical |
| Jul | 83 | Tropical |
| Aug | 84 | Tropical |
| Sep | 84 | Tropical |
| Oct | 80 | Warm |
| Nov | 73 | Refreshing |
| Dec | 69 | Refreshing |
UV index in Portland in September
Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Portland peaks around June 16 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 4 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 5 | 6 | 7 | 10 | 11 | 11 | 11 | 11 | 10 | 7 | 5 | 4 |
| Level | Moderate | High | High | Very high | Extreme | Extreme | Extreme | Extreme | Very high | High | High | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 5 | Moderate |
| Feb | 6 | High |
| Mar | 7 | High |
| Apr | 10 | Very high |
| May | 11 | Extreme |
| Jun | 11 | Extreme |
| Jul | 11 | Extreme |
| Aug | 11 | Extreme |
| Sep | 10 | Very high |
| Oct | 7 | High |
| Nov | 5 | High |
| Dec | 4 | Moderate |
Air quality in Portland in September
Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.
Air quality in Portland is worst in July — around 20 µg/m³ PM2.5 (moderate), about 3.2× the cleanest month (November, 6 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 8 | 9 | 12 | 12 | 16 | 17 | 20 | 13 | 11 | 6 | 6 | 7 |
| Level | Good | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 8 | Good |
| Feb | 9 | Good |
| Mar | 12 | Good |
| Apr | 12 | Good |
| May | 16 | Moderate |
| Jun | 17 | Moderate |
| Jul | 20 | Moderate |
| Aug | 13 | Moderate |
| Sep | 11 | Good |
| Oct | 6 | Good |
| Nov | 6 | Good |
| Dec | 7 | Good |
Where is Portland?
Portland sits at 27.9°N, 97.3°W, 43 ft above sea level, in United States. The nearest listed city is Corpus Christi, 6.8 mi away.
Topography around Portland
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Portland.
Within 2 miles, the terrain around Portland has only modest variations in elevation — a maximum elevation change of 56 ft around an average of 16 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 115 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 394 ft.
The land around Portland is covered by water (47%) and artificial surfaces (25%) within 2 miles, water (38%) and cropland (33%) within 10 miles, and water (33%), grassland (23%) and cropland (20%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Portland (27.8773°, -97.3239°, elevation 43 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).