Portland Weather in August
United States · Oceanic climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
August in Portland sees average temperatures ranging from a low of 15.3°C (59.5°F) to a high of 29.2°C (84.6°F), with a mean of 21.5°C (70.7°F). Compared to the annual average of 11.9°C (53.4°F), this month is 9.6°C warmer than the yearly norm. This is the hottest month of the year, reaching 29.2°C (84.6°F) on average. Precipitation averages 13.2mm, making it approximately 106.0mm drier than the monthly average of 120.0mm. The city receives an average of 11.9 hours of sunshine per day during August, with relative humidity averaging 58.9%. Wind speeds reach an average maximum of 15.9 km/h. For travelers, this month offers a hottest month of the year experience in Portland, with drier-than-average conditions compared to the rest of the year.
Portland's climate is similar to Seattle but with slightly warmer summers and cooler winters. I visited during the famous rose festival in June and found the weather ideal. The data shows that the best time to visit is June to September, when the rainfall is minimal and the city's famous outdoor culture thrives. The winter months are grey and wet but the city's coffee shop culture makes it cozy.
August vs Adjacent Months
| Metric | July | August | September |
|---|---|---|---|
| Mean Temp | 21.3°C (70.3°F) | 21.5°C (70.7°F) | 18.3°C (64.9°F) |
| Rainfall | 5.1mm | 13.2mm | 65.2mm |
| Sunshine | 13.5 hrs | 11.9 hrs | 10.0 hrs |
| Humidity | 58.2% | 58.9% | 66.4% |
| Wind | 16.4 km/h | 15.9 km/h | 15.3 km/h |
| Rainy Days | 4.0 | 4.8 | 9.4 |
Seasonal Context
August falls in Summer in the Northern Hemisphere. Summer brings the warmest conditions of the year with the longest daylight hours. For travelers visiting Portland in August, the data indicates favorable conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Portland in August?
The average temperature in Portland during August ranges from 15.3°C (59.5°F) to 29.2°C (84.6°F), with a mean of 21.5°C (70.7°F).
How much does it rain in Portland in August?
Portland receives an average of 13.2mm of precipitation in August, spread across approximately 4.8 rainy days.
What should I pack for Portland in August?
Based on August weather data, pack layers including light jackets and t-shirts, plus an umbrella.
Is August a good time to visit Portland?
August is a good time to visit Portland, with comfortable temperatures and manageable rainfall. However, it is the hottest month — consider early morning or evening activities.
Other Months for Portland
Cities with Similar August Climate (Oceanic)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 45.52°, -122.68°. Timezone: America/Los_Angeles. Last updated: 2026-07-30.