Monthly pollen calendar, and when allergy season hits hardest

No significant pollen

Outdoor pollen is usually quiet, but indoor dryness and dust can still keep allergy symptoms going.

Alder, hazel

Early tree pollen can start on mild days. Sensitive people sometimes notice symptoms before they expect them.

Birch, oak, ash

Spring allergy season starts to feel real here. If your symptoms return every year, this is when forecast-checking should become a habit.

Oak, birch, pine

This is often the hardest spring month. Tree pollen peaks and daily outdoor decisions matter much more.

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 starts to climb. This is where people often think their spring allergy is gone, then get hit again.

Ragweed, mugwort, nettle

One of the worst months for autumn allergy symptoms. If late-summer sneezing returns every year, this is usually why.

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.