Pollen Count & Forecast for Tokyo

Tokyo’s spring allergy season (February–April) is dominated by Cedar and Cypress pollen; Japanese Cedar (Cryptomeria japonica) is prolific in the Tama hills and Shinjuku Gyoen; Japanese Cypress (Chamaecyparis obtusa) follows through April. Summer sees high Grass (Poaceae) counts, originating from the Tama River and Yoyogi Park. Autumn (September–November) has elevated Ragweed (Ambrosia) and Mugwort (Artemisia) levels near Ueno Park.

Seasonal winds from the Kanto Plain transport cedar particles into the city basin; urban heat islands maintain high temperatures. High humidity across the Tokyo Bay area triggers Mould (Alternaria, Cladosporium) growth; spores are common in damp subway tunnels and the Imperial Palace Gardens.