Pollen Count & Forecast for Trondheim

Trondheim’s spring allergy season (April-June) is dominated by Birch and Alder pollen; Birch (Betula) prolific throughout Bymarka and along Nidelva riverbanks; Alder (Alnus) widespread along the Ladestien coastal trail. Rowan (Sorbus aucuparia) contributes significantly from the nearby forest edges. Summer (June-August) has high Grass (Poaceae) pollen levels, originating from Marinen and the grass fields at Festningsparken.

Coastal winds and the surrounding hills move pollen across the fjord, leading to localised high concentrations in city streets. Autumn has high Mould (Alternaria, Cladosporium) spore counts, from decaying leaf litter in Bymarka and damp soils in the Elgeseter area.