Pollen Count & Forecast for Boston

Boston’s spring allergy season (April–June) is dominated by Oak and Maple pollen; Oak (Quercus) common in the Arnold Arboretum and Public Garden; Maple (Acer) widespread along the Emerald Necklace. Birch (Betula) contributes significantly from the banks of the Charles River. Summer (June–August) sees high Grass (Poaceae) pollen levels, originating from Franklin Park and Boston Common. Autumn sees Ragweed (Ambrosia) from the Muddy River banks and urban fringes.

Breezes from the Atlantic Ocean often clear pollen; western winds carry higher concentrations from inland forests. Autumn and winter see high Mould (Alternaria, Cladosporium) counts, from damp leaf litter in the Back Bay Fens and marshy city areas.