August warmer than usual in Lapland, summer as a whole marked by a record heatwave and varying weather
Photo: Heli Sariola.According to the Finnish Meteorological Institute’s statistics, the average temperature in August varied between 12 and 17 degrees at most observation stations in Finland. In Lapland, August was warmer than usual, but in other parts of the country, the average temperature for the month was normal or lower than normal.
In August, there were eight days when temperatures exceeded 25 Celsius, which is one day less than average. In the southern and western parts of the country, there were 1 to 2 days less than usual with temperatures exceeding 25 degrees per observation station, while in Lapland, there were 2–4 more days with temperatures exceeding 25 degrees than usual. This was exceptionally high in some places.
The highest temperature of the month, 31.1 degrees, was measured in the Rovaniemi train station on 1 August. The lowest temperature, –3.6 degrees, was recorded at the Tulppio observation station in Savukoski, on 31 August.
Less precipitation in the east than usual, unusually abundant precipitation in places in Lapland
In many places in the eastern part of the country, precipitation levels were lower than usual in August. Rainfall on the western coast and in Lapland was more abundant than usual in places, its levels were even unusually or exceptionally high in Northern Lapland. According to preliminary results, the Saariselkä travel centre observation station recorded the most precipitation for the month with a result of 142.6 mm. The lowest amount of precipitation was 27.8 mm, which was recorded at the Kestilä observation station in Siikalatva. The highest daily rainfall, 43.9 mm, was recorded at the Lampela observation station in Lieksa on 10 August.
The number of thunderstorms was normal in August. Approximately 24,600 cloud-to-ground lightning discharges were observed in Finland, while the average is 24,300.
The number of hours of sunshine nation-wide was usual or higher than usual: the amount of sunshine was chiefly ranged from 180 to 270 hours.
Average summer temperature close to normal, weather types varied
The entire summer (June–August) was warmer than usual in Lapland: the summer’s average temperature was 0.8–1.2 degrees higher than usual. Elsewhere in Finland, this summer’s average temperature was 0–1 degrees higher than normal. The average summer temperature for the whole of Finland was 14.9 degrees Celsius.
This summer’s highest temperature was 32.6 degrees, which was recorded at the Oulu airport on 31 July. The lowest temperature, –3.6 degrees, was measured at Tulppio in Savukoski, on 31 August.
From May to August, there were 33 days with temperatures exceeding 25 degrees in some parts of Finland, while the long-term average for the period is 36 days. This is the lowest number of days in May-August with temperatures exceeding 25 degrees since 2017, when there were only 19 such days. This year, there were no days in May when temperatures exceeded 25 degrees, and there were only two in June.
However, many observation stations, especially in the central and northern parts of the country, recorded more days with temperatures exceeding 25 degrees than normal, and in many places they recorded an unusual or exceptional amount: for example, a total of 25 days with temperatures exceeding 25 degrees were recorded in Tähtelä, Sodankylä, which is a new record in statistics starting from 1961. The previous record, 24 days, was from 2014. On the other hand, a 26-day heatwave with daily temperatures over 25 degrees was recorded at Lake Meltosjärvi in Ylitornio, which is a new record in Lapland; the previous observation station-specific record for heatwaves was 14 days in 1972.
During a heatwave which began on 11 July and lasted for 22 days, the highest temperature of the day in Finland was over 30 degrees each day; this was the longest heatwave with temperatures exceeding 30 degrees in Finland’s measurement history. According to an international study published in August, the heatwave in July was about two degrees hotter due to climate change and at least ten times more likely than without human-caused global warming.
Finland’s summer was characterised by varying weather types: in June, temperatures were normal or lower than usual. July also began with mostly chilly temperatures and heavy rainfall owing to low-pressure systems. After the long heatwave, the weather at the end of August varied again between warmer than usual and chillier than usual. With the exception of the long heatwave, the summer was at times chillier than average, and especially in the south, the number of summer days, meaning days when the highest temperature rises to at least 20 degrees, was well below normal in places.
Summer saw lower lighting activity than usual
Finland’s summer, meaning June–August, was rainy in the coastal areas of the country and in the areas of Inari and Enontekiö. Precipitation levels during the summer were lower than usual in the eastern and central parts of the country and in Southern and Central Lapland. According to preliminary data, the highest amount of precipitation was recorded in Pirttikoski, Hämeenlinna, totalling 312.9 mm. The Nuorgam station in Utsjoki recorded the lowest amount of rainfall over the summer with a result of 117.9 mm.
There were fewer thunderstorms than on average. By the end of August, approximately 75,000 cloud-to-ground lightning discharges were observed, while the average for a normal period is about 113,000 cloud-to-ground lightning discharges. In May-June, lightning activity was very low, while in July-August lightning activity was closer to the average. The largest number of cloud-to-ground lightning discharges were detected in Lapland.
In the summer, the amount of sunshine was mainly at the norm in the southern and central parts of the country, and slightly above normal in the north.
Further information:
Weather statistics from the Climate Service on weekdays, tel. +358 600 1 0601 (€ 4.06/min + local network fee)