Pollen Count & Forecast for Oslo

Oslo’s spring allergy season (March–May) is dominated by Birch and Alder pollen; Birch (Betula) prolific in the Nordmarka forest and Slottsparken; Alder (Alnus) widespread along Akerselva riverbanks. Hazel (Corylus) contributes significantly from early March. Summer (June–July) sees high Grass (Poaceae) pollen levels, originating from Vigeland Park and Ekeberg hill.

The city’s position between the Oslofjord and surrounding hills creates a basin; this trap holds pollen during calm weather. Autumn and winter see elevated Mould (Alternaria, Cladosporium) spore counts, from decomposing leaf litter in Oslomarka forests and damp riverside corridors.