Finland in September: where is it warmest?
In September, Turku is the warmest place with 15 °C by day, Rovaniemi, Lapland the coolest with 12 °C. 2 of 7 destinations have good holiday weather.
All destinations in September, warmest first
Long-term averages for the month: daytime high, sea, sunshine and rainy days.
Finland in September: quick answers
Finland in September: where is it warmest?
The warmest places in September are Turku (15 °C), Espoo (15 °C) and Helsinki (15 °C).
Finland in September: where is the sea warmest?
The sea is warmest at Espoo (15 °C), Helsinki (15 °C) and Porvoo (15 °C).
Finland in September: where is the weather best?
The best holiday weather in September – warm, sunny and dry – is in Turku, Espoo and Helsinki.
Finland month by month
Finland: weather & best time to visit
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). Sources & licences