Pollen Count & Forecast for Merton, Croydon

Merton’s spring allergy profile is dominated by Birch and Oak pollen, peaking March-May from extensive street trees and woodlands, notably Wimbledon Common and Morden Hall Park; summer sees high Grass pollen counts, prevalent May-July from open spaces, Mitcham Common, and River Wandle riparian zones.

Urban topography and the Wandle Valley microclimate can trap and concentrate local pollen plumes; prevailing south-westerly winds also transport regional allergens. Autumn’s late-season challenge is Mould spores, peaking September-November due to damp leaf litter decomposition in green spaces and shaded urban environments.