Oregon pollen and allergy seasons
Oregon has an early tree season and an intense grass season in the Willamette Valley in late spring and early summer.
Twelve month pollen calendar
What is active in August
Cities in Oregon
No tracked cities yet for Oregon.
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 Oregon for ozone, dust, and smoke readings by city.
The Oregon allergy season
Allergy levels in Oregon peak in June, when grass pollen runs highest. The season moves through tree pollen around March, grass in June, weed pollen such as ragweed in August. Levels start to climb around February. The lowest pollen levels of the year arrive in January.
Common questions
When does allergy season start in Oregon?
Pollen levels in Oregon usually begin climbing in February and reach their highest point in June.
What is the worst month for allergies in Oregon?
June is typically the worst month in Oregon, driven by grass pollen.
When does ragweed season end in Oregon?
Ragweed pollen in Oregon usually fades by the end of September, after the first hard frost in colder areas.
When is the best time for allergies in Oregon?
January usually brings the lowest pollen levels of the year in Oregon.