average early september temperatures in helsinki finland
The average sea tempeature is 13 Â°C (55.4 Â°F). The average temperature in Helsinki in September is quite mild at 11.5 Â°C (52.7 Â°F). Afternoons can be mild with average high temperatures reaching 15 Â°C (59 Â°F). Overnight temperatures are generally a little cool with an average low of 8 Â°C (46.4 Â°F). In September the range/ variation of daily mean temperatures is 7 Â°C (12.6 Â°F). The weather in September is somewhat dry with rain once in a while. Just 71mm (2.8in) of H2O descends during on average 15 days.