Unusually mild spring in Finnish Lapland
Finnish Meteorological Institute statistics showed that the average temperature for March-May varied between nearly five degrees Celsius in the southwest of the country to just over one degree below freezing in Enontekiö. In Lapland the average temperature was unusually high in many places. In other parts of the country, average temperatures were normal or slightly above normal. Temperatures were lower than usual mainly in the southeast of Finland.
Precipitation was below average in a large part of the country, especially in the southeast. Only in the areas of Pirkanmaa, Central Finland, and South Ostrobothnia, and locally in parts of the north, and central areas of Lapland was precipitation higher than normal. Spring precipitation was highest, 142 millimetres, at the Hytiälä observation station in Juupajoki. Precipitation was lowest, 39.5 millimetres, at the Lepola observation station in Lappeenranta.
Only one hot day in May
Average temperatures for May varied between about +3 and +4 degrees in the north of Lapland to nearly 10 degrees in the south. In southern and eastern parts, the average temperature was generally about 0.5 to 1 degree lower than the averages for the statistical normal period of 1991–2020. However, in Lapland, the average temperature was just under one degree above normal. Elsewhere the average temperature was close to the averages for the normal period.
The month began under chilly conditions in most areas but warmed up as the month went on so that day temperatures went above 20 degrees on a few days at the end of the month. The month's highest temperature, 25.4 degrees, was recorded on 25 May at the Oulunsalo Pellonpää observation station in Oulu. This was also the only time in May that the temperature exceeded 25 degrees. The month's lowest temperature, -18.7 degrees, was recorded on 5 May at the Kilpisjärvi village observation station in Enontekiö.
In many areas May was a month of either normal levels of precipitation or slightly less, especially in an area extending from the east to southern parts of Finnish Lapland. In Central and Northern Lapland there was more precipitation than usual, while there was considerable fluctuation in the west, with South Ostrobothnia and Uusimaa getting an unusually high amount. In the southwest and the southwest archipelago, there was less precipitation than usual.
The highest amount of precipitation recorded in May was 77.4 millimetres at the Helsinki-Vantaa Airport observation station. The airport also set the month’s record for precipitation in a single day, 27.3 millimetres on 26 May. Precipitation was lowest, 12.2 millimetres, at the Lepola observation station in Lappeenranta.
About midway through the month tens of centimetres of snow still lay on the ground at observation stations at high elevations in Northern Lapland, but by the end of May the snow had melted from all observation stations.
Ground discharges of lightning numbered about 1,400, which is significantly below 8,000, the average for 1960–2021.
The number of hours of direct sunlight was close to the average, but slightly below average near the South Coast.
Weather statistics from Climate service tel. 0600 1 0601 (€ 4.01/min + local call charge)