Hay Fever Season Commences in Central Germany, But Pollen Levels Remain Moderate

The telltale signs are here: sneezing fits, itchy eyes, and a runny nose. For many residents of Saxony, Saxony-Anhalt, and Thuringia, the dreaded hay fever season has officially begun. However, those suffering from pollen allergies can breathe a small sigh of relief, at least for now. According to Christina Endler, a researcher at the Center for Medical-Meteorological Research of the German Weather Service (DWD), the current pollen burden is relatively moderate due to the fluctuating weather conditions experienced in the region.

"Currently, we are primarily dealing with pollen from hazel and alder trees," Endler explained. This is a typical start to the hay fever season in this part of Germany. However, she noted a contrast to the previous year, where the concentration of hazel and alder pollen had already reached significantly higher levels during the same period. The early onset and intensity of pollen seasons have become a growing concern for allergy sufferers in recent years, often leading to extended periods of discomfort and reliance on medication.

The reason for the comparatively milder pollen levels this year, so far, lies in the erratic weather patterns that have characterized the past few weeks. "The cold phases in recent weeks briefly caused plant development to stagnate," Endler elaborated. The periods of cold weather effectively put a pause on the natural processes of plant growth and pollen release, offering a temporary respite for allergy sufferers. This stagnation is a direct consequence of the plants’ sensitivity to temperature changes, as they require a certain level of warmth to initiate and sustain their reproductive cycles.

However, the respite has not been continuous. Endler pointed out that the states of Saxony, Saxony-Anhalt, and Thuringia have also experienced periods of milder weather, which, in turn, have stimulated plant development and pollen production. This alternating pattern of cold and mild spells creates a fluctuating pollen count, making it difficult for allergy sufferers to predict and manage their symptoms effectively. The unpredictable nature of the pollen season can be particularly challenging, requiring constant vigilance and adjustments to medication dosages.

Diving deeper into the timeline of the current season, Endler indicated that hazel blossoming began on a large scale at the end of January. "In Saxony-Anhalt and Thuringia, the hazel blossom started only a few days earlier based on current reporting, while in Saxony, the hazel blossom began on average about two weeks earlier." This regional variation highlights the influence of microclimates and local weather conditions on the timing of plant phenology. The earlier onset in Saxony could be attributed to localized warmer temperatures or specific environmental factors that promoted earlier flowering.

The alder blossom, another significant contributor to early-season pollen allergies, commenced in some areas as early as the first half of February. The overlapping blossoming periods of hazel and alder trees can exacerbate allergy symptoms for individuals sensitive to both types of pollen, leading to a prolonged and more intense period of discomfort. The simultaneous release of pollen from multiple sources increases the overall concentration in the air, making it more challenging to avoid exposure and manage allergic reactions.

Endler emphasized the crucial role of weather conditions in influencing pollen release and dispersal. "Sunny and dry weather generally promotes pollen release and pollen distribution, and thus pollen flight," she stated. Warm temperatures and low humidity create optimal conditions for pollen grains to become airborne and travel long distances, increasing the risk of exposure for allergy sufferers in wider geographical areas.

Conversely, "Changeable weather, with persistent and frequent precipitation, minimizes pollen flight because the pollen is increasingly washed out of the air." Rain acts as a natural air purifier, effectively removing pollen grains from the atmosphere and reducing the concentration in the air. This is why allergy sufferers often experience a noticeable reduction in symptoms during or immediately after periods of rainfall. However, the relief is often temporary, as pollen levels can rebound quickly once the weather clears and conditions become more favorable for pollen release.

Looking beyond the immediate short-term, Endler highlighted a concerning long-term trend. "Overall, there has been a trend towards an earlier start to flowering in the last 30 years – among other things, because the winters have been comparatively mild recently." This shift towards earlier blossoming is widely recognized as a consequence of climate change, with rising temperatures and altered weather patterns disrupting the natural cycles of plants. The gradual warming of winters allows plants to initiate their growth and reproductive processes earlier in the year, extending the pollen season and increasing the overall exposure to allergens.

To quantify this shift, Endler referred to phenological observations from two distinct periods: 1961 to 1990 and 1991 to 2020. "Considering the periods 1961 to 1990 and 1991 to 2020, phenological observations showed that the start of hazel blossoming in Saxony, Saxony-Anhalt, and Thuringia shifted forward by two to three weeks." This significant shift underscores the profound impact of climate change on plant phenology and the resulting consequences for allergy sufferers.

The implication of this trend is clear: "It is therefore increasingly likely that hazel blossoming will begin as early as January or early February in the future." This earlier onset of the pollen season poses significant challenges for allergy management, requiring individuals to be more proactive in monitoring pollen levels and taking preventative measures. The extended pollen season also increases the overall burden of allergic disease, impacting productivity, quality of life, and healthcare costs. As climate change continues to accelerate, further shifts in plant phenology are anticipated, requiring ongoing research and adaptation strategies to mitigate the impact on public health.