Pollen Count & Forecast for Mexico City

Mexico City’s dry season (January–March) is dominated by Ash and Alder pollen; Ash (Fraxinus) prolific in Bosque de Chapultepec and Viveros de Coyoacán. Alder (Alnus) and Oak (Quercus) contribute significantly from the hills of Desierto de los Leones and the Ajusco range. Summer and autumn (June–October) see high Grass (Poaceae) pollen levels, originating from Xochimilco canals and the Cuemanco area.

The high-altitude basin traps pollen against the surrounding mountains, leading to localised high concentrations. The rainy season sees elevated Mould (Alternaria, Cladosporium) spore counts, from decomposing leaf litter and damp southern forest environments.