Pennsylvania pollen and allergy seasons
Pennsylvania has a spring tree season, grass in early summer, and a heavy ragweed season in the fall.
Twelve month pollen calendar
What is active in September
Cities in Pennsylvania
No tracked cities yet for Pennsylvania.
Today and worst today come from live readings where available. Typical shows the usual level for this month from the seasonal profile.
Pollen is only half of what's in the air. See today's air quality in Pennsylvania for ozone, dust, and smoke readings by city.
The Pennsylvania allergy season
Allergy levels in Pennsylvania peak in September, when ragweed pollen runs highest. The season moves through tree pollen around April, grass in June, weed pollen such as ragweed in September. Levels start to climb around March. The lowest pollen levels of the year arrive in January.
Common questions
When does allergy season start in Pennsylvania?
Pollen levels in Pennsylvania usually begin climbing in March and reach their highest point in September.
What is the worst month for allergies in Pennsylvania?
September is typically the worst month in Pennsylvania, driven by ragweed pollen.
When does ragweed season end in Pennsylvania?
Ragweed pollen in Pennsylvania usually fades by the end of October, after the first hard frost in colder areas.
When is the best time for allergies in Pennsylvania?
January usually brings the lowest pollen levels of the year in Pennsylvania.