Temperatures reached at least 20 degrees Celsius in many parts of the country last weekend – perfect conditions for birch trees to start releasing pollen, which is at its most irritating in the spring.

And as a string of sunny, breezy days are now expected, sufferers are unlikely to get relief any time soon as prolonged rainfall would be needed to stop birch trees in their tracks, meteorologist Jörg Riemann from the Berlin Meteogroup told Monday’s Die Welt newspaper.

“It’s far too warm for this time of year,” Riemann said. “The absolute upper limit for this time of year is 20 degrees, anymore shouldn’t be happening.”

Germany’s alder trees were almost ready to begin pumping out pollen at the beginning of the year due to an unusually warm January, but were stopped in their tracks by the extreme cold snap in February.

Birch pollen does not usually start triggering hay fever around the middle of April, giving a period of relief for sufferers in March, when Alder tree pollen has generally settled down.

“This will not happen this year,” Riemann told Die Welt.

Hay fever season is much longer than it was 25 years ago due to climate change, which has extended by 11 days the time in which enough birch pollen is in the air to cause an allergic reaction, since 1989. The itch-inducing pollen now swirls around for about 36 days of the year.

More than a third of Germans have some sort of allergy, and hay fever – a pollen allergy – is the most common according to recently published data by polling company Forsa.

Of the 1,000 people the polling organisation asked, more than half described their affliction as a burden.

DPA/The Local/jcw