August in Portland averages a daily high of 25.8°C with nights around 15.2°C. Expect roughly 9.5 wet days totalling 87.1mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Portland is June–September.
Based on PORTLAND JETPORT, ME US (4km), 1995–2024. 30 years of August data.