Pollen Count & Forecast for Brussels

Brussels’ spring allergy season (March-May) is dominated by Birch and Alder pollen; Birch (Betula) dense in the Sonian Forest and Bois de la Cambre; Alder (Alnus) widespread along River Senne valley areas. Oak (Quercus) contributes significantly from the Parc du Cinquantenaire. Summer (May-July) sees high Grass (Poaceae) pollen levels, originating from the lawns of Parc de Laeken and along Canal Charleroi-Brussels.

The city’s basin topography and narrow streets in the Pentagon district trap allergens, leading to localised high concentrations. Autumn and winter see high Mould (Alternaria, Cladosporium) spore counts, from decomposing leaf litter in the Sonian Forest and damp environments along River Senne riverbanks.