Portland weather in August
August in Portland: hot, dry, with clean air — an excellent time to visit.
#5 of 12 months in Portland · #172 of 604 destinations to visit in August · comfort 86/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Portland climate normals — August
| Daytime high | 31°C / 87°F | 🥵 hot |
|---|---|---|
| Nighttime low | 16°C / 61°F | |
| Feels like (high) | 30°C / 86°F | |
| Rainfall | 7 mm / 0.3 in | ☀️ dry |
| Rainy days | 2 days | |
| Humidity | 55% | 🍃 comfortable |
| Dew point | 12°C / 54°F | |
| Sunshine | 11.7 h/day | |
| Daylight | 14.1 h | |
| Wind | 12 km/h / 7 mph | |
| Air quality (US AQI) | 34 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Portland in August — FAQ
- Is August a good time to visit Portland?
- August in Portland: hot, dry, with clean air — an excellent time to visit. It ranks #5 of 12 months for Portland on SeasonMap's comfort score (86/100).
- What is the weather like in Portland in August?
- In August, Portland averages a daily high of 30.6°C and a low of 15.9°C, with about 6.7 mm of rain over roughly 1.8 rainy days.
- What is the air quality in Portland in August?
- Portland has a mean US Air Quality Index of about 34 in August.