Monthly Pollen Calendar

No significant pollen

Winter. No pollen but indoor allergens (dust mites, mold) can be an issue. Keep indoor humidity at 40-60%.

Alder, hazel

Early tree pollen begins in mild climates. Alder and hazel can start releasing pollen on warmer days.

Birch, oak, ash

Spring pollen season begins in earnest. Birch is a major allergen in many temperate regions.

Oak, birch, pine

Peak tree pollen month. Oak and birch dominate. This is typically the worst month for spring allergy sufferers.

Pine, grass species

Tree pollen declines as grass pollen starts. Pine pollen creates visible yellow dust but is less allergenic.

Grass species

Grass pollen peaks. Rain temporarily washes pollen from the air, providing brief relief.

Grass (declining)

Grass pollen subsides. Often the most comfortable month for allergy sufferers in many regions.

Ragweed, mugwort

Autumn weed pollen season begins. Ragweed is a major trigger in North America and parts of Europe.

Ragweed, mugwort, nettle

Peak weed pollen month. Ragweed and mugwort are at their worst. The most challenging month for autumn allergies.

Weeds (declining)

Weed pollen decreases. First frost ends the pollen season in most areas.

No significant pollen

Pollen season is over. Focus on indoor allergen management as heating season begins.

No significant pollen

Winter. Watch out for indoor allergens: dust mites, pet dander, and mold from poor ventilation.