Milder birch pollen season – in the short term

One consolation for allergy sufferers may be that this year’s birch pollen season is predicted to be milder than last year. But the pollen season has been extended over time, and it looks set to continue in that direction.

Sneezing, watery eyes and stuffy noses are everyday life for about a third of Swedes this year as we enter this year’s pollen season.

There is already pollen from hazel and alder in the southern parts of the country. The risk of high levels is high on Gotland and along parts of the Baltic Sea coast due to pollen that has accompanied the winds from Poland.

Lighter this year

But the birch pollen season may be relatively mild this year according to Åslög Dahl, biologist and responsible for the pollen lab at the University of Gothenburg.

– The birches bloomed intensively last year and then they don’t get as big leaves this year, so they can’t produce pendants until this year, she says.

– This does not mean that it will be free (read: from birch pollen), but it will be milder than last year.

Later season

The season started late (in the south) because the winter was long and cold. But compared to how it has looked historically, the season generally starts earlier today.

– There is no doubt that something has happened in terms of the average advance of the season since we started measuring 45 years ago, says Åslög Dahl.

It depends on the temperature, carbon dioxide content and land use, according to her.

– Since everything points to it continuing to get warmer, it will probably continue to change.

New species have also arrived, such as wormwood ambrosia. It only blooms at the end of August and came here with bird seed. And if we bring in more species that bloom later, there is a risk that the pollen season will be extended even further.

– We could get pollen all year round, but that hasn’t happened yet, says Åslög Dahl.