Pollen volumes in the air vary from moderate to heavy in southern and central areas, Turku University's aerobiological unit said on Monday. Flowering of alder trees has mostly concluded in the south and remains light elsewhere.
There is still little birch pollen up north. However last week warm air flowing in Russia brought birch pollen into northern and eastern Finland.
The pollen situation tends to fluctuate with heavier years alternately with lighter ones, based primarily on the previous summer's weather. Following last year's chilly summer, this year levels are considerably lower than they have been in the past two years.
Thanks to warmer weather that approached 20 degrees in some areas over May Day weekend, southern and central Finland are close to so-called thermal summer, which the Finnish Meteorological Institute (FMI) defines as starting when the mean daily temperature remains steadily above 10 degrees Celsius. Current forecasts do not predict any declines in temperatures.
Warm, wet April
The FMI says April was unusually mild and rainy through most of the country. Average temperatures ranged from +4 degrees in the south to -2 in Finnish Lapland's north-western arm. In Northern Karelia and Eastern Lapland, April was more than two degrees warmer than usual.
The area stretching from Uusimaa to Central Finland received more than twice as much rain as the long-term average, as did the western coastal area of Lapland. Only in North Karelia and North Lapland did temperatures remain below the long-term mean.
