Project (Allergy Radar) aims to improve the hay fever forecasts and to decrease the amount of hay fever symptoms patients experience. provides a live and national overview of the intensity of hay fever symptoms that hay fever patients experience (nose, eyes and lungs). Hay fever patients report their symptoms via the website. The Pollen planner on the website provides a daily long-term forecast on the start and duration of the pollen season of the most important hay fever species. is coordinated by the Environmental Systems Analysis Group of Wageningen University, the Leiden University Medical Center and triptic.

Aim of the project

The daily registration of the severity of nose-, eye- and lung-symptoms are used for scientific research of Wageningen University and the Leiden University Medical Center. The objectives of are:

  • Increase our knowledge on hay fever
    We want to determine where and when people in The Netherlands experience hay fever symptoms. Furthermore, we aim to determine at which pollen concentration people experience symptoms.
  • Increase knowledge on the cause of hay fever
    We want to determine which biological, environmental, medical and socio-economic factors explain the (intensity and variability of) hay fever symptoms.
  • Validating research results
    We want to validate the current hay fever forecasts and develop new forecasts.
  • Realize contact with the target groups
    We want to actively communicate the new knowledge to hay fever patients and medical specialists to allow these groups to prevent or reduce hay fever symptoms.


Severity of hay fever symptoms

Hay fever patients are asked to participate in the research by reporting the amount of hay fever symptoms they experience on their eyes, lungs and their nose. The severity of symptoms vary from 1 (no symptoms) to 10 (maximum amount of symptoms). Before patients can participate they have to fill in a questionnaire in which we ask for background information.


Every day the Pollenplanner recalculates the timing of the start and duration of the pollen season for the most important pollen plants in The Netherlands based on the new weather predictions. The underlying forecasting models are made by the Environmental Systems Analysis group in the context of the Dutch phenological network De Natuurkalender. The analyses are based on daily pollen counts of the Leiden University Medical Center in Leiden, the Elkerliek Hospital in Helmond and the Delmenhorst pollen monitoring station in Germany.


We expect to significantly improve the Dutch hay fever forecasts. With these improved forecasts, patients can significantly improve their quality of life as they will be better able to take preventive measures in time.