Portland, OR weather in September
In September, Portland sees highs around 75°F and lows around 55°F: mild, with some rain. There are about 7 days with rain. Great for outdoor plans.
- Normal high
- 75°F
- Normal low
- 55°F
- Wet days
- 7
- 1.5 in total
- Muggy days
- 0
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 79°F | 70°F |
| Normal low | 57°F | 52°F |
| Chance of a wet day | 18% | 30% |
| Sunrise / sunset | 6:32 am / 7:49 pm | 7:07 am / 6:53 pm |
| Daylight | 13.3 h | 11.8 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Pacific Time).
A typical September day
- 6 am56°Fdew point 52°F
- 9 am61°Fdew point 52°F
- Noon69°Fdew point 51°F
- 3 pm74°Fdew point 50°F
- 6 pm71°Fdew point 51°F
- 9 pm64°Fdew point 53°F
NOAA hourly normals (local standard time) from Portland Intl Airport (6 mi away); average wind 6 mph.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F18 of 30
- Hot dayshigh 90°F or more1 of 30
- Muggy daysdaily mean dew point 65°F or more0 of 30
- Wet daysat least 0.01 in of rain or melted snow7 of 30
- Notable rainat least 0.10 in4 of 30
- Freezing nightslow 32°F or below0 of 30
- Snow on the groundsnow depth 1 in or more0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 1.5 in; a dry September brings about 0.9 in and a wet one about 1.9 in (25th and 75th percentiles). About 1 day brings half an inch or more.
How September varies from year to year
- Warmest September, 1991-20201991: average high 79°F
- Coolest September2019: average high 70°F
- Wettest September2013: 5.6 in
- Driest September1993: no measurable precipitation
- Highest reading96°F (September 2, 2006)
- Lowest reading41°F (September 30, 2019)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 81°F | 75°F | 63°F |
| Normal low | 59°F | 55°F | 48°F |
| Wet days | 4 | 7 | 14 |
| Comfortable days | 15 | 18 | 11 |
| Daylight | 14.1 h | 12.5 h | 10.9 h |
Highs change by -6°F from August and -12°F into October.
Nearby alternatives in September
- Drier: Bend, OR121 mi · high 76°F · 2 wet days
- Cooler: Cannon Beach, OR67 mi · high 68°F · 9 wet days
How Portland ranks in September
- Normal high285th warmest of 378 cities; 5th of 6 in Oregon
- Wet days134th driest of 378
- Comfortable days27th most of 342
Heating and cooling
September has 70 heating degree days and 70 cooling degree days (base 65°F), 3% of the year's total heating and cooling demand.
Questions
How hot is Portland in September?
The normal high is 75°F and the normal low is 55°F. From 1991 to 2020 the hottest September reading was 96°F (most recently on September 2, 2006).
Does it rain a lot in Portland in September?
About 7 days in September have at least 0.01 in of precipitation, and the normal total is 1.5 in. The wettest September in 1991-2020 was in 2013 (5.6 in); the driest was in 1993, with no measurable precipitation.
Is September a good time to visit Portland?
September ranks 3rd of 12 months on our comfort score for Portland (74 out of 100). It has about 18 comfortable days and about 1 day at 90°F or hotter. The best month is June.
Where the numbers come from
- Temperature: Portland Kgw-Tv (USC00356749), 0.7 mi WSW of the city center, 159 ft (127 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Rain, snowfall, snow depth, frost dates and humidity and wind by hour: Portland Intl Airport (USW00024229), 5.9 mi NE of the city center, 19 ft . NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Portland International Airport (726980-24229), 6.0 mi NNE of the city center, 22 ft . Hourly observations, 1991-2020.
- Not available for this location: cloud cover (no station close enough or similar enough in elevation).