Press release archive: 2017

Days were cool and nights warm in September

9.10.2017 10:30

The average temperature for September was near normal, except for Lapland. The eastern part of the country received more than the usual amount of precipitation; the rainfall recorded in Virolahti was almost 160 mm.

Photo: Eija Vallinheimo

Photo: Eija Vallinheimo

According to Finnish Meteorological Institute statistics, the average temperature in September was about one degree higher than usual, while the average temperature in the rest of the country was near normal. The last time Finland experienced a colder September than usual was nine years ago.

Due to abundant cloudiness, daytime temperatures remained below the typical values in many areas, whereas night-time temperatures were higher than usual.

The month's highest temperature, 19.6°C, was recorded in Kaarina on 24 September. The month's lowest temperature, -3.8°C, was recorded in Naruska, Salla, on 6 September.

Rainy in the east, drier in the west

September saw higher levels of precipitation than usual in the eastern part of Finland, Kainuu and Koillismaa, whereas the western part of the country and Lapland were drier than usual. In terms of precipitation, the month was divided into three periods: the beginning and the end were mainly dry due to high pressure, but heavy precipitation was received in some areas towards mid-September.

The month's highest amount of precipitation, 157.5 mm, was measured in Virolahti in the southeast of Finland. It was unusually high, which means that rainfall as heavy as this is only seen about once every ten years. The least precipitation was recorded in Näkkälä, Enontekiö, where the monthly rainfall was 17.6 mm.

Due to abundant cloudiness and fog, the whole country had significantly less sunshine than usual. The sunshine total was above the long-term average only in northern Lapland.

Further information:

Weather and statistics for September (in Finnish): http://ilmatieteenlaitos.fi/syyskuu

http://ilmatieteenlaitos.fi/ilmasto
http://www.ilmastokatsaus.fi/

The Finnish Meteorological Institute's Meteorologists on Twitter: http://twitter.com/meteorologit
The Finnish Meteorological Institute's science news coverage on Twitter: http://twitter.com/IlmaTiede