August in Lahti averages a daily high of 21.3°C with nights around 11.7°C. Expect roughly 11.6 wet days totalling 65.2mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Lahti is June–August.
Based on HEINOLA ASEMANTAUS, FI (32km), 1995–2024. 30 years of August data.