Pollen Count & Forecast for Colchester

Colchester experiences peak seasonal allergies from March to July. Spring brings dominant arboreal pollen: Birch and Hazel are prolific March-April from High Woods Country Park and urban street trees; Oak and Plane pollen follow April-May, prevalent in Castle Park and along the Roman walls. Early summer (May-July) sees high grass pollen counts, originating from the River Colne floodplains and surrounding agricultural meadows.

The city’s historical urban fabric, including the Roman walls and dense housing, can create sheltered microclimates, trapping pollen and intensifying localised exposure. Late summer through autumn introduces elevated mould spore levels; these originate from damp leaf litter in parks and decomposing vegetation within the Colne Valley’s humid environments, prolonging allergy symptoms until winter.