According to Finnish Meteorological Institute, the expiration of the heat period has reached the average number of the long term hot days at some sites. The average number of hot days has, as yet, been primarily exceeded in Western Finland: at Helsinki-Vantaa Airport, Turku, Suomusjärvi, Jokioinen, Pori and Kuorevesi.
At Jomala weather station in Södersund, Mariehamn four hot days 3.-4.7. and 7.-8.7. have been measured. Prior to this, according to the statistics measured by the former weather station located closer to the sea, there has been on the average only one hot day in July in Mariehamn.
Heat period which started end of June, extended to the beginning of July first in the Eastern part of Finland in Savo, Pohjois-Karjala, and Kainuu. So far, the highest temperature this summer, 31 C, was observed 5th of July in Puumala.
Hot day is defined as a day during which the maximum temperature reaches at least 25,1 °C. In June the number of hot days was below the long-term average. The maximum number of hot days in June was three and were recorded at two sites, Utti and Niinisalo. The earliest hot days, on 10th of June, were observed at Utsjoki-Kevo and Ivalo. The rest of the hot days occurred between Mid Summer Day (25.6) and the end of June in the Western part of Finland except the hot days at Pudasjärvi, Utti, and Lappeenranta.