Thermal spring began in southern and central areas already on February 18 and 19. This indicates that spring has arrived over one month early in Finland this year. On average, thermal spring begins in south-western Finland on March 26 and a week or so later in early April in central parts of the country.
In eastern and northern parts of Finland, spring officially began when March turned into April, with Central Lapland the last to join the fold on April 4 and 5. On average, thermal spring begins in mid-April in Lapland, and not until the end of April in northernmost regions.
Thermal spring refers only to the temperature, and this makes it possible for Finns to declare spring officially open even while there is still half a metre of snow on the ground in Lapland, North Ostrobothnia and Kainuu.
