In brief
The alder and hazel pollen season has begun.
The inflorescences of these trees are ripe and disperse pollen in the air when conditions are favorable. Currently, low temperatures and rain events tend to limit this dispersal.
People who are more sensitive or who are locally exposed may already be affected by allergy symptoms. During this risk period, it is recommended to take all necessary precautions as concentrations can quickly increase in case of dry weather.