Helsinki weather in August
Temperature, sea and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Good
Best time to visit: June – August
What is the weather like in Helsinki in August?
In August, Helsinki is mild: daytime highs average 20 °C, and nights cool down to about 14 °C. The sea averages 17.4 °C – bracing, so a wetsuit helps for longer swims. The sun shines for around 8 hours a day. Rain is frequent, with about 13 rainy days and 79 mm in total. All in all, August is a good month for a holiday in Helsinki.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 81 | 78 | 59 |
| Day | 21° | 20° | 15° |
| Night | 15° | 14° | 10° |
| Sea | 17° | 17° | 15° |
| Sun | 10 h | 8 h | 5 h |
| Rain days | 13 | 13 | 10 |
More details for August
- Daylight
- 15 h 47 min05:32 – 21:18
- UV index
- 4 · moderateclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or more
- Wind
- 17 km/haverage daily peak
- Cloud cover
- 62 %on average
- Hot days
- 0 days30 °C or more
- Snow days
- 0 days1 cm or more of fresh snow
- Time zone
- UTC+3Europe/Helsinki
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %83 %
- Few rainy daysweight 30 %37 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in August
- Wetsuit for longer swims
- Sunscreen
- Sunglasses & sun hat
- A jumper for the evenings
- Rain jacket or umbrella
Helsinki in August: quick answers
Is Helsinki hot in August?
No. In August, Helsinki is mild: daytime highs average 20 °C and nights drop to about 14 °C.
Can you swim in Helsinki in August?
Only if you don't mind cold water: in August the sea averages just 17.4 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Helsinki in August?
Rain is frequent, with about 13 rainy days and 79 mm in total.
Helsinki month by month
The whole year in HelsinkiAll destinations: FinlandWhere to go in AugustSea temperature in August
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0)