Weather in Portland in August 2025
- August is usually the hottest month of the year in Portland;
- August is usually the driest month of the year in Portland
Average weather
Average temperature in Portland in August
The temperature in August is +88°F on average, with a range between a maximum of +106°F during the day and a minimum of +54°F at night.
The average maximum temperature goes down 14% by the end of the month, compared with the beginning of the month, from +86°F to +79°F.
Is Portland warm or cold in August?
Portland is typically warm in August.
Maximum temperatures go up compared to the previous month from +82°F to +82°F. The minimum temperature also goes up from +57°F to +57°F.
It’s generally warm, but pack a long-sleeve shirt for evenings.
August is the hottest month in Portland, here is the comparison with other months:
Climate in Portland in August
| July | August | September | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +82°F | +82°F | +77°F | ||||
| Min. temperature | ||||||
| +43°F | +45°F | +37°F | ||||
| Max. temperature | ||||||
| +108°F | +106°F | +106°F | ||||
| Rainfall | ||||||
| 37 mm | 16 mm | 49 mm | ||||
| Wind | ||||||
| 1 m/s | 1 m/s | 1 m/s | ||||
| Humidity | ||||||
| 64% | 63% | 68% | ||||
| Air pressure | ||||||
| 1016 HPa | 1015 HPa | 1015 HPa | ||||
| Sunny days | ||||||
| 13 | 12 | 10 | ||||
| Cloudy days | ||||||
| 11 | 12 | 10 | ||||
| Rainy days | ||||||
| 7 | 6 | 10 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
August often has better weather than July. The temperature levels stay the same in the area of +82°F for average maximum temperature during the day. As August arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 37 mm to 16 mm. It feels drier, as humidity decreases from 64% to 63%. The average wind speed doesn’t change much during August, staying around 1 m/s. The days becoming less sunny, going from 13 sunny days in July to 12 in August.
Next month (September) brings a further decline in the weather.
Wind
The average wind speed is 2 m/s getting up to 3 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Portland is gradually decreasing during August, going from 3 m/s to 2 m/s over the course of the month.
Rain
How was the weather last August in Portland?
Climate Change Over the Years
The climate in Portland in August has not changed that much over the last 43 years.
The average temperature was the lowest in 2011 (+61°F) and the highest in 2015 (+67°F). The driest year was 1985 with only 736 mm of rainfall, and the wettest year was 2021 with 4296 mm.
FAQ
Is August a good time to visit Portland?
Can you sunbathe in Portland in August?
Is Portland rainy in August?
Is it sunny in Portland in August?
Other cities in USA
Monthly weather in Portland
Source of the data
For this page, we’ve looked at the typical weather in Portland, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.