October in Helsinki averages a daily high of 9.5°C with nights around 4.7°C. Expect roughly 13.8 wet days totalling 74.5mm. Demanding conditions — pack for it and plan indoor options.
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 October data.