Pollen Count & Forecast for San José

San José’s dry season (December–April) is dominated by Mexican Cypress (Cupressus lusitanica); trees are frequent in the Escazú hills and Parque La Sabana. African Star Grass (Cynodon nlemfuensis) grows along the Torres River; Kikuyu Grass (Pennisetum clandestinum) is common in pastures around the city periphery. Strong trade winds carry pollen from Oak (Quercus) forests in the nearby Cordillera Central.

The valley basin geography traps allergens between mountain ranges; air is stagnant during morning hours. The green season (May–November) has high Mould (Aspergillus, Penicillium) spore counts; spores are in humid conditions near the Maria Aguilar River and damp urban environments.