Press release 14.5.2012

Spring started with a cool April

Measurements conducted by the Finnish Meteorological Institute show that, in the whole of Finland, the mean temperature for April 2012 was somewhat lower than usually, ranging from slightly over +3° C in Southern Finland to just under -4° C in Enontekiö, Lapland.
Photo: Tuija Vuorinen

Measurements conducted by the Finnish Meteorological Institute show that, in the whole of Finland, the mean temperature for April 2012 was somewhat lower than usually, ranging from slightly over +3° C in Southern Finland to just under -4° C in Enontekiö, Lapland.

In most parts of the country, the mean temperature differed from the long-term average for April by 1 to 2 degrees. Furthest in the southwest, however, temperatures were close to the long-term average. The highest temperature for the month was 17.1° C, measured in Artukainen, Turku on 22 April, while the lowest temperature, -28.7° C, was measured in Kevojärvi, Utsjoki on 2 April.Thermal spring proceeded slowly in early April, but at the end of the month it had already reached Central Lapland, which is more or less normal. Thermal spring begins when the mean daily temperature rises permanently above 0° C.

More rain than usual

In most of Finland, precipitation for April was 40–60 mm. The least rain was measured in Lapland, where in some areas the figure was under 30 mm. When compared against the long-term average, there was clearly more rain than usually in almost all of Finland. In the Åland Islands, on the coast of Ostrobothnia and in some parts of Southern Lapland, there was twice as much rain as normally.Among individual observation stations, the greatest rainfall was measured in Jomala, the Åland Islands, which had 73 mm of rain. The least rain, 21 mm, was measured in Kilpisjärvi, Enontekiö. The highest daily precipitation was 26.2 mm, measured in Klemettilä, Vaasa on 20 April.

An exceptional amount of snow remaining in Western Lapland

The Finnish Meteorological Institute’s measurements show that in early April, a continuous blanket of snow covered all but the westernmost areas of the country. At the end of the month, the continuous snow cover had receded to a line extending from Kainuu to the Bay of Bothnia. In Western Lapland, the snow cover at the end of April was exceptionally thick for the time of the year; the thickest snow, 100 cm, was measured in Kenttärova, Kittilä.Some places received over 20 cm of snow during a heavy snowfall in Pirkanmaa on 2 April. The snow cover measured in Härmälä, Tampere on the next day was 47 cm, or the thickest for the entire winter season.

For its monthly weather data, the Finnish Meteorological Institute has started using the statistics calculated for the years 1981–2010 as the normal period. The change in mean temperatures between the normal periods 1981–2010 and 1971–2000 is the greatest in April. During the new normal period, the mean temperatures for April in the whole of Finland are 0.5 to 1.0 degrees higher than the mean temperatures for the previous normal period. In many places, the mean for the highest temperatures in April has risen more than one degree. Especially in Southern Finland, precipitation figures for April are lower than during the previous normal period.

Additional information on the statistics from the Climate Service Centre, climateservice@fmi.fi