September was cool with low precipitation
According to statistics of the Finnish Meteorological Institute, the average temperature for September varied between about +6 degrees Celsius in the northern Lapland and about +12 degrees in the southwestern archipelago. September was close to the long-term average in Lapland and elsewhere cooler than usual, in places unusually cool. Statistically, the temperatures deviated from the average for the reference period 1991-2020 by approximately 1-2 degrees.
The highest temperature in September, 19.5 degrees, was recorded on 6 September at the observation station at Jussarö, Raseborg. The lowest temperature was -7.5 degrees, recorded at Ylivieska Airport on 8 September.
September experienced mostly lower precipitation than usual, and precipitation levels remained unusually low in southern Lapland and in central parts of the country. Åland and a part of Northern Lapland experienced more rain than usual.
Based on preliminary information, the highest level of precipitation (84.3 mm) was recorded at the Saariselkä Tourist Information Centre in Inari, while the lowest level of precipitation (14.8 mm) was recorded at the Kelloselkä observation station in Salla. The largest daily rainfall was in Kemie, in Tohmajärvi, where 37.8 mm was recorded on 15 September.
First snow appeared at the end of the month
On the last day of the month, the first recorded snowfall happened in Kainuu, where 2 cm of snow was recorded at the observation stations of both Puolanka Kotila and Paljakka. In addition, there was 1 cm of snow at the Mustavaara observation station in Ristijärvi.
In September, approximately 35-170 hours of sunshine were recorded, mostly in southern coastal areas, the least in North Karelia and Northern Lapland. The number of sunshine hours in the south was close to normal, further north less than normal or unusually low. Only 57 cloud-to-ground discharges were observed in September, well below the average of 4400 for the whole month.
Climate statistics Weather statistics from Climate service tel. 0600 1 0601 (€ 4.01/min + local call charge)
Meteorologists use the word exceptional when a weather phenomenon occurs on average no more than once every 30 years. A phenomenon is called rare when it occurs less frequently than once in ten years, on average.