August in Helsinki averages a daily high of 20.7°C with nights around 13.7°C. Expect roughly 11.8 wet days totalling 81.1mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Helsinki is June–August.
Based on HELSINKI KAISANIEMI AWS, FI (0.9km), 1995–2024. 30 years of August data.