Portland, OR weather in August
Portland is warm and mostly dry in August: highs average 81°F and nights drop to about 59°F. There are about 4 days with rain. This is the peak of the warm season in Portland. A great month for outdoor plans.
- Normal high
- 81°F
- Normal low
- 59°F
- Wet days
- 4
- 0.5 in total
- Muggy days
- 0
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 82°F | 79°F |
| Normal low | 59°F | 58°F |
| Chance of a wet day | 10% | 16% |
| Sunrise / sunset | 5:54 am / 8:39 pm | 6:31 am / 7:51 pm |
| Daylight | 14.7 h | 13.3 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 August day
- 6 am60°Fdew point 54°F
- 9 am66°Fdew point 55°F
- Noon74°Fdew point 54°F
- 3 pm80°Fdew point 53°F
- 6 pm78°Fdew point 54°F
- 9 pm70°Fdew point 55°F
NOAA hourly normals (local standard time) from Portland Intl Airport (6 mi away); average wind 7 mph.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F15 of 31
- Hot dayshigh 90°F or more4 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow4 of 31
- Notable rainat least 0.10 in2 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 0.5 in; a dry August brings about 0.1 in and a wet one about 0.8 in (25th and 75th percentiles). Days with half an inch or more are rare.
How August varies from year to year
- Warmest August, 1991-20202017: average high 85°F
- Coolest August1995: average high 77°F
- Wettest August2004: 2.7 in
- Driest August1998: no measurable precipitation
- Highest reading103°F (August 3, 2017)
- Lowest reading47°F (August 25, 1993)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
August compared with July and September
| July | August | September | |
|---|---|---|---|
| Normal high | 80°F | 81°F | 75°F |
| Normal low | 58°F | 59°F | 55°F |
| Wet days | 4 | 4 | 7 |
| Comfortable days | 16 | 15 | 18 |
| Daylight | 15.3 h | 14.1 h | 12.5 h |
Highs change by +1°F from July and -6°F into September.
Nearby alternatives in August
- Warmer: Leavenworth, WA172 mi · high 87°F · 2 wet days
- Cooler: Cannon Beach, OR67 mi · high 69°F · 6 wet days
How Portland ranks in August
- Normal high301st warmest of 378 cities; 5th of 6 in Oregon
- Wet days74th driest of 378
- Comfortable days28th most of 341
What to pack for Portland in August
- Sunglasses and sunscreen – about 14.1 hours of daylight and highs near 81°F
Heating and cooling
August has 13 heating degree days and 156 cooling degree days (base 65°F), 4% of the year's total heating and cooling demand.
Questions
How hot is Portland in August?
The normal high is 81°F and the normal low is 59°F. From 1991 to 2020 the hottest August reading was 103°F (August 3, 2017).
Does it rain a lot in Portland in August?
About 4 days in August have at least 0.01 in of precipitation, and the normal total is 0.5 in. The wettest August in 1991-2020 was in 2004 (2.7 in); the driest was in 1998, with no measurable precipitation.
Is August a good time to visit Portland?
August ranks 4th of 12 months on our comfort score for Portland (73 out of 100). It has about 15 comfortable days and about 4 days 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).