High season for grasses

We are entering into the period of massive grass pollen production, a very bad time for hayfever sufferers. They should remain cautious and follow the treatment prescribed by their doctor.

In brief

Many grass species are currently in bloom and their pollen may induce the typical hayfever symptoms.

On Thursday, 68 grains/m³ of air were measured in Brussels.


Latest measure: 
Thursday, 19 May, 2022
20212022Mean 2012 - 2021threshold value06 May13 May20 May27 May03 Jun10 Jun17 Jun24 Jun01 Jul08 Jul15 Jul22 Jul020406080100120140160180200220240260280grains / m³

Good to know

  • The risk of allergy varies greatly from one person to another. But from 50 grains of grass pollen per m³ of air, the majority of people allergic to this type of pollen are likely to experience symptoms.
  • A few useful recommendations: avoid outdoor activities, wear sun glasses, do not dry linen outside, rinse your nose regularly, wash your hair before going to sleep.
  • Typical allergy symptoms such as runny nose, cough or shortness of breath (in case of asthma) can easily be mistaken for a cold, flu or coronavirus infection. However, fever and body aches should be given special attention as they might be caused by viral infection. It is recommended to call your general practitioner in case of doubt.
  • The standardized pollen detection technique allows retrospective measurement of the levels from samples taken the day before. Samples are analyzed manually during the working days by optical microscopy.
  • Follow us too on Twitter @AirAllergy !