Helsinki Weather in August
Finland · Subarctic climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
August in Helsinki sees average temperatures ranging from a low of 14.0°C (57.2°F) to a high of 20.1°C (68.2°F), with a mean of 17.2°C (63.0°F). Compared to the annual average of 6.8°C (44.2°F), this month is 10.4°C warmer than the yearly norm. Precipitation averages 97.1mm, making it approximately 28.0mm wetter than the monthly average of 69.0mm. This is the wettest month of the year, with 97.1mm of precipitation and around 19.6 rainy days. The city receives an average of 11.1 hours of sunshine per day during August, with relative humidity averaging 79.5%. Wind speeds reach an average maximum of 21.3 km/h. For travelers, this month offers a temperature experience in Helsinki, with wetter-than-average conditions compared to the rest of the year.
If you're planning outdoor activities in Helsinki, daylight is the variable that matters most. I did a sea kayak tour in June at 10pm — full sun, 18°C, surreal. December gives you 6 hours of gray light, which limits everything. The Nordic summer (June-August) is the outdoor window: 18-22°C, 19 hours of daylight, perfect for island-hopping by ferry. Winter is its own adventure: -5°C, snow cover from January-March, and the sauna-ice-swim cycle is a Helsinki essential. Pack windproof layers year-round — the Baltic breeze cuts hard. September brings fall colors and fewer tourists; my favorite hiking month.
August vs Adjacent Months
| Metric | July | August | September |
|---|---|---|---|
| Mean Temp | 17.9°C (64.2°F) | 17.2°C (63.0°F) | 12.9°C (55.2°F) |
| Rainfall | 79.9mm | 97.1mm | 69.6mm |
| Sunshine | 13.8 hrs | 11.1 hrs | 8.6 hrs |
| Humidity | 75.2% | 79.5% | 80.3% |
| Wind | 21.4 km/h | 21.3 km/h | 21.9 km/h |
| Rainy Days | 20.4 | 19.6 | 15.6 |
Seasonal Context
August falls in Summer in the Northern Hemisphere. Summer brings the warmest conditions of the year with the longest daylight hours. For travelers visiting Helsinki in August, the data indicates favorable conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Helsinki in August?
The average temperature in Helsinki during August ranges from 14.0°C (57.2°F) to 20.1°C (68.2°F), with a mean of 17.2°C (63.0°F).
How much does it rain in Helsinki in August?
Helsinki receives an average of 97.1mm of precipitation in August, spread across approximately 19.6 rainy days. This is the wettest month of the year.
What should I pack for Helsinki in August?
Based on August weather data, pack layers including light jackets and t-shirts, plus an umbrella.
Is August a good time to visit Helsinki?
August is a good time to visit Helsinki, with comfortable temperatures and manageable rainfall. However, it is the wettest month — plan indoor activities and pack rain gear.
Other Months for Helsinki
Cities with Similar August Climate (Subarctic)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 60.17°, 24.94°. Timezone: Europe/Helsinki. Last updated: 2026-07-30.